iPhone 8




Last modified: 

July 20, 2017

About the iPhone 8
Average consumers and passionate fans alike are gearing up for the biggest change to happen to the iPhone since the device’s unveiling in 2007. With technology advancements slowing, yet cravings for high-end technology and cutting-edge design rising, Apple will be expected to push harder than it ever has to get buyers in stores to pick up its latest device. In an apparent effort to appease consumer demand, Apple’s 10th anniversary smartphone, the iPhone 8, is expected to be a monumental improvement for the iPhone lineup. Here are the innovations insiders and expert analysts alike are expecting to be featured within Apple’s iPhone 8.

iPhone 8 Specifications

Release DateSeptember 8th, 2017
CameraVertical 3D Dual-Lens16 Mega Pixels"Invisible" front camera underneath display
DisplayNew 5.8" OLED Display4K Retina DisplayCurved OLED DisplayApple Pencil Compatibility
ColorsWhiteJet BlackSilverGoldRose Gold
Features5.8" OLED DisplayIris Scanning SecurityTouch ID within displayContoured glass casing w/ metal frame
FeaturesLarge Power Button4mm bezels around edge of display256GBWireless Charging
Dimensions143.59 x 70.94 x 7.57 mm5.65 x 2.79 x 0.30 in

iPhone 8 Images

Contains Rumors


iPhone 8 Size and Dimensions

According to the most recent dimension leaks and available iPhone 8 case information, it has been determined that the iPhone 8 will be smaller than the iPhone 7 Plus, yet larger than the iPhone 7. In fact, according to the iPhone 8 dimension information leaked to iDrop News, the iPhone 8 will be larger than the iPhone 7 in every aspect including thickness. But it’s important to note the iPhone 8 will be smaller in physical size than the iPhone 7 Plus, while featuring a .3-inch larger display.

  • Metric: 143.59 x 70.94 x 7.57 mm
  • Imperial(US): 5.65 x 2.79 x 0.30 in

iPhone 8 Expected Release Date

Last year, Apple announced its long-awaited iPhone 7 on September 7 – and it’s quite obvious why Apple would seize the opportunity to associate the model number with the corresponding date. It only seems logical that Apple would continue this canny pattern when launching its latest iPhone. It’s also worth noting that the days at which Apple has launched their flagship phones are varied (the iPhone 6s was launched on a Friday, and the iPhone 7 was launched on a Wednesday).

Because of our previous knowledge of Apple’s iPhone announcement dates, the spontaneous days of the week they fall on, and the logical nature of releasing a numbered iPhone with its corresponding calendar date, we can safely estimate Apple’s iPhone 8 will be announced this coming fall on Friday September 8, 2017. However, that is if all goes according to plan. Recent trials and tribulations in Apple’s supply chain have pushed analysts’ estimates for the iPhone 8’s release somewhere between October and December, 2017.

Hidden Touch ID

Apple has patented technology that would allow the company to place its famed Touch ID system underneath the iPhone 8’s display, which would be a revolutionary advancement in security technology. Not to mention Touch ID underneath the display would make a physically larger display possible by removing the extra space on the front of the device that’s currently occupied by the Touch ID home button. Though, it has been reported that Apple’s suppliers haven’t been able to keep up with demand for the hidden Touch ID technology, and the technology itself hasn’t been the most reliable. This hidden Touch ID system could be a game changer, however various Android devices currently feature a fingerprint sensor on the rear, a loophole Apple has been rumored to take if Touch ID underneath the display doesn’t work the way it’s intended. It’s unlikely that Apple will ship the iPhone 8 with a rear-mounted fingerprint sensor due to its clunky and unrefined nature, but we won’t know for sure if Apple will be able to work out the new technology’s kinks until later this year.

Function Area

The Function Area is rumored to be a portion of the iPhone 8’s 5.8-inch display set aside for a virtual Home button, other virtual buttons, and possibly a hidden Touch ID fingerprint reader. Renowned Apple analyst Ming-Chi Kuo of KGI Securities originally made the prediction back in February — adding that the final device should be around the same size as the 4.7-inch iPhone 7, but with a much larger display. Similarly, the New York Times reported in September 2016 that the iPhone 8 would ditch physical buttons for digital ones.

The Function Area is expected to adapt to the app being used, allowing access to buttons and actions relevant to app currently running. For example, while the Music app is open, track, seek, and pause buttons could be readily available within the Function Area, ready to use at any given time. The possibilities of the Function Area are essentially limitless, only restricted by the app designers’ imaginations.

Possible Name Change

It’s clear that Apple has some major surprises in the works for the iPhone 8 and one of them could even be a name change. While “iPhone 8” is the most commonly used moniker when referencing Apple’s next iPhone, there have also been rumors speculating the next iPhone could be called the iPhone X. However, the most widely accepted alternative name for the iPhone 8 is “iPhone Edition” which has been recognized several times this year. Additionally, sources close to Apple’s supply chain referred to the iPhone 8 as the “iPhone Edition” when providing iDrop News with leaked information about Apple’s secretive smartphone.

Vertical Dual-Lens Camera with 3D Technology

Apple is currently investigating the possibility of equipping its iPhone 8 with a next-generation dual-lens camera module that’s capable of capturing vivid images with a three dimensional (3D) depth of field. Allegedly, Apple is working directly with its current dual-lens camera supplier, LG Innotek, to develop and test these new, highly-advanced camera modules. This is more than likely due to LG’s exclusivity in providing Apple with dual-lens camera modules for its iPhone 7 Plus, but also because LG has previous experience developing a smartphone capable of capturing 3D images.

Back in 2011, albeit to mixed reviews, LG introduced its iconic Optimus 3D smartphone, which was touted as the first of such devices to boast authentic 3D-quality imaging capabilities. The Optimus 3D was a bit of a hit-or-miss device, however, what users seemed to love most about it, was that the smartphone could seamlessly transition between standard 2D and 3D photos with the mere toggle of a switch – something Apple might be keen to include on the upcoming iPhone 8.

Also likely to help Apple in its pursuit to a 3D-capable camera, is the company’s 2015 acquisition of LinX Computational Imaging — the Israel-based motion imaging firm known best for having developed its own 3D mapping interface.

Also worth noting, the current dual-lens camera setup found on the rear of the iPhone 7 Plus will make its way to the iPhone 8 however the lenses are expected to be rotated vertically, increasing the camera’s depth of field effectiveness when the phone is held horizontally in AR and VR scenarios.

Revamped 3D Touch System

Ming-Chi Kuo, a well-respected Apple analyst, indicated that Apple’s forthcoming iPhone 8 will sport “a new, improved, 3D Touch system for enhanced pressure sensitivity.”

Noting that Apple’s high-end iPhone 8 will boast an advanced, flexible OLED display panel, (which will curve slightly at the edges so as to cover the entire front surface of the device), Kuo sounded the alarm that Apple’s existing 3D Touch panels would be incompatible with such display. As such, the company is planning to switch from its current “FBCB” sensor employed in the iPhone 6s/7, to a new film-based 3D Touch layer. This will not only be more flexible, but will also boast much higher touch sensitivity, opening the door to the company employing a wider range of 3D Touch gestures on the device.

Kuo noted, however, that because OLED panels are generally more fragile than their LCD counterparts, Apple will also employ a metal, structural reinforcing component of some sort. This will be to supplement the new film-based 3D Touch layer around the delicate, curved edges of the device. What’s unknown at this point is whether that metal structure will be a visible component, or merely an under layer resting deeper beneath the display, itself.

Nearly Edge-to-Edge Display

A bezel-less iPhone 8 with an OLED display was one of ten different prototypes that Apple was reportedly testing, however rumors of an iPhone with a fully curved OLED display have been dormant for some time. And according to the most recent leaks acquired by iDrop News, it seems as if two iPhone 8 prototypes have made their way through Apple’s advanced stages of testing and neither of them have a fully edge-to-edge display. There is room for a larger 18.5:9 aspect ratio display however, as the iPhone 8’s bezels are believed to measure only 4mm around the entire device.

New 5.8-inch Display Size

Famed KGI Securities analyst Ming-Chi Kuo suggested that Apple is preparing to defect from its current, two-variant iPhone sales strategy next year — opting, in addition to the standard LCD-equipped 4.7- and 5.5-inch iPhones, to construct and offer a radically redesigned, super-premium 5.8-inch model, boasting a curved OLED display, among other technological advancements.

In his report, Kuo suggested that this mysterious new 5.8-inch iPhone 8 will contain the most “new stuff.” Therefore, out of all three 2017 iPhone models, Apple’s top-tier 5.5-inch Plus variant will no longer be the company’s most premium offering. But rather, the all-new 5.8-inch iPhone 8 will take center stage as Apple’s premium iPhone offering next fall.

Advanced Siri Capabilities

Another rumor, which surfaced from DigiTimes, alleges that Apple’s forthcoming iPhone 8 will ship with “enhanced Siri capabilities.” However, the report failed to mention what exactly those “enhanced capabilities” will entail.

The report did state that Apple is gearing up to incorporate a slew of advanced new Siri features, thanks in part to the Artificial Intelligence-based (AI) software acquired through the company’s August, 2016 acquisition of Turi.

“Apple acquired Australia-based machine learning startup Turi in August 2016, aiming to further strengthen the functionality, as well as the market share, of its Siri intelligent personal assistant,” reads the DigiTimes report. “Meanwhile, market sources have also indicated that Apple’s next-generation iPhone devices are likely to come with enhanced Siri.”

Durable Steel Frame

Apple’s next generation iPhone will abandon aluminum, opting instead for “two reinforced glass panels and a metal frame in the middle,” reminiscent of the iPhone 4 design. The metal bezel will allegedly “be made of stainless steel using a forging process to enhance its sturdiness and reduce costs and manufacturing time.”

The DigitTimes report, which cites “sources from the upstream supply chain” also claims that manufacturing for the steel frame will be handled by Foxconn Electronics and US-based Jabil, the same two companies that were responsible for manufacturing the frame for the iPhone 4.

Wireless Charging

It’s looking more and more certain that the iPhone 8 will feature wireless charging capabilities. A report has surfaced indicating that Taiwan-based Lite-On Semiconductor has been tapped to manufacture half the GPP bridge rectifiers needed to support fast wireless charging in Apple’s next-gen flagship smartphone.

Lite-On Semiconductor, a manufacturer of discrete and analog integrated chip components, did not comment on the report that it had entered Apple’s global supply chain, although its stock rallied by its daily 10% limit to $0.91 when the story emerged on January 19.

Wireless charging for smartphones has been a subject of much discussion and rumor over the years. The rumors intensified when Apple received a patent in 2012 for wireless charging utilizing near field magnetic resonance.

Last year, Energous announced a collaboration with long-time Apple supplier Dialog Semiconductor to manufacture and market hardware components. Energous is a US startup that specializes in long-range wireless charging technology. A year before the Dialog deal was even publicized, Energous CEO obliquely referred to a development and licensing agreement with a “tier one” consumer electronics company, fueling further speculation about integration of such technology into future iPhones.

Laser-Guided Facial Recognition System

Timothy Arcuri, of the market research and financial services firm, Cowen and Company, told his firm’s investors in a research note this week that Apple’s iPhone 8 flagship — unlike its moderately improved, iPhone 7s and iPhone 7s Plus counterparts — will launch featuring what he described as “some form of facial/gesture recognition supported by a new laser sensor and an infrared sensor mounted near the front-facing camera.”

Thus far, a standard and universal facial recognition protocol has yet to be implemented into any of Apple’s major products. However, Apple has used modified iterations of the underlying technology, for example, with the introduction of advanced object and facial recognition features built into its Photos app.

A standalone, hardware sensor, though — akin to the kind that Arcuri is describing — has not yet been explored by Apple. And, furthermore, there have thus far been no rumors or hints from Apple’s vast supply chain that such a feature is even impending. Sure, Apple could always change its mind and course at any time, but of all the ‘iPhone 8’ rumors we’ve heard so far, this facial recognition laser simply is not among them. Although Tim Cook, himself, did recently hint that Apple had big plans in the works for Augmented Reality (AR)-based protocols — so, take it with a grain of salt.

Water Resistance

The iPhone 8 will carry a water- and dust-resistance rating of IP68, according to industry sources cited by The Korea Herald. That’s a step above the IP67 water-resistance rating that the iPhone 7 and iPhone 7 Plus currently carry.

“Apple’s iPhone 8 will feature the IP68 rating as part of drastic upgrades marking the 10th anniversary of the iPhone this year,” the anonymous source told The Korea Herald.

From a practical standpoint, that means that Apple’s next generation of iPhone will be able to withstand being submerged in water of depths up to 1.5 meters (just under 5 feet) for up to 30 minutes, according to the International Electrotechnical Commission, the organization that publishes the guidelines for the IP standards.

The “6” found within the IP rating, denotes an essentially dustproof device. The iPhone 7, which Apple only calls “splash resistant,” carries an IP67 rating. That means that the device is rated to be immersed in water under 1 meter, or 3.3 feet, for 30 minutes. While keeping a device dry is the safest way of ensuring it won’t be damaged, many tests have found that the iPhone 7 is more water resistant than advertised.

Tap to Wake

A ‘Tap to Wake’ feature, similar to the one employed by Samsung on some of its premium Galaxy S handsets, will be coming to iPhone this year. However, the feature will reportedly be an exclusive to Apple’s uber-premium, curved OLED-equipped iPhone 8, which has been codenamed ‘Ferrari’.

The reason why ‘Tap to Wake’ will be exclusive to Apple’s high-end iPhone remains unclear. However, it’s quite possible that the superior, battery-sipping technology OLED display, which has long been rumored to debut as a cornerstone feature of Apple’s iPhone 8, is in some way a prerequisite factor to make the feature work properly.

Apple Pencil Compatibility

Published by the U.S. Patent and Trademark Office, Apple’s patent (No. 20160364091) is described only as “Devices and Methods for Manipulating User Interfaces with a Stylus,” according to Patently Apple; and is essentially a further expansion on previous patent filings we reported on earlier this year, suggesting that Apple Pencil functionality could one day come to the company’s smaller, touchscreen-enabled devices.

Apple’s most recent patent application discusses the inclusion of “multiple new sensors” being embedded underneath the device’s display, allowing for deeper interaction with Apple Pencil on iPhone. For instance, the filing describes various sensors that would be able to detect the nearness of Apple’s Pencil to the display — prior to launching “a special menu” showing options for carrying out stylus-based actions.

Additionally, not only will the stylus be able to open certain pre-specified apps directly from the iOS lock screen, but the iPhone-friendly stylus tool will also be able to do things like draw or trace pictures, write to enter text, and more — meaning that Apple Pencil functionality on the iPhone, if indeed it ultimately comes to be, won’t be limited to just the iOS Notes app.

iOS 11

Apple’s iPhone 8 will launch this fall with iOS 11 preinstalled. iOS 11 brings a host of new features and improvements to the iPhone’s operating system including APFS, a revamped control center, native screen recording, and much more. Learn more about iOS 11, here.

How Much Will the iPhone 8 Cost?

The iPhone 8 is likely to be a “premium model.” Combine that with the fact that Apple is expected to keep the price points for the iPhone 7s and 7s Plus the same as their predecessors, and you have the recipe for a very expensive iPhone.

Of course, predicting just how expensive the iPhone 8 could be is speculation, but current pricing strategies are a decent gauge for what to expect. For example, the iPhone 7 and iPhone 7 Plus are currently priced between $649 and $969, depending on model. Since the smaller of the two phones runs $120 cheaper than its larger brother, it’s not too much of a venture to say that a premium iPhone 8 could cost  $120 to $200 more than an iPhone 7s Plus. That could mean a 256-gigabyte iPhone 8 would run you $1,200 and would line up with Apple’s aim to increase its margins on its high-end flagship – however, that’s a high estimate. Analysts currently predict the 128 GB iPhone 8 will cost $999 while a 256 GB model will cost $1,099.

Latest iPhone 8 News

  1. Report Claims Apple Now Plans to Build Its Own OLED Displays

  2. Conflicting New Leak Suggests Rear Touch ID for iPhone 8

  3. iPhone 8 and iPhone 7s Models Delayed Again, Report Claims

  4. Apple Forced to Lease iPhone 8 Production Equipment to Suppliers

  5. Apple’s iPhone 8 Just Made TSMC’s 86-Year-Old Founder a Billionaire

  6. iPhone 8 Expected Add Rear-Facing 3D Laser, But Apple Should Act Fast

  7. Panic at Apple Due to These 4 iPhone X Features

  8. iPhone 8’s Wireless Charger Rumored to Be Delayed, Sold Separately

  9. More Global Supply Chain Issues Delay iPhone 8 Production

  10. Ming-Chi Kuo’s Top 7 iPhone Predictions for 2017

  11. Advanced 3D/AR Facial Scanner Reported to Replace iPhone 8’s Touch ID

  12. Why Apple’s iPhone 8 Won’t Be Called the ‘iPhone 8’

  13. iPhone 8 Video Leak Confirms Predicted Design

  14. Samsung Boosts OLED Display Production Ahead of iPhone 8

  15. iPhone 8 to Feature Ultra-Fast Charging via USB-C to Lightning

  16. ‘Vertical Cavity Surface Emitting Lasers’ Confirmed for iPhone 8

  17. Subtle iOS 11 Tweaks Hint at Major Design Changes for iPhone 8

  18. Apple Is Gorging Smartphone Parts at the Expense of Its Rivals

  19. iPhone 8 Design Seemingly Confirmed By New Cases

  20. Samsung to Unveil Galaxy Note 8, Before iPhone 8, This August

  21. iPhone 8 Screen Protector Surfaces Matching Concept Renders

  22. Apple to Unveil iPhone X with Advanced AR Features in September

  23. iPhone X May Not Be the First Device with a Hidden Fingerprint Sensor

  24. iPhone X Supplier Confirms 3D Facial Recognition Sensors Are Coming

  25. iPhone 8 Wallpapers for Download

  26. Leaked iPhone X Images Backup Latest Renders, Rumors

  27. Step into the Future: iPhone X Running iOS 11

  28. 5G Networks: The Future of Wireless Explained

  29. iPhone 8 Rumor Roundup: Release Date, Price, Features, and More

  30. More Leaked Images Hint iPhone 8 Will Feature Rear Touch ID

  31. Leak Confirms iPhone 8 Will Be Larger Than iPhone 7 in Every Way

  32. iPhone 8 Case Shows Size Comparison Between iPhone 7 and 7 Plus

  33. Reliable Report Backs up iPhone 8 Display-Embedded Touch ID Rumors

  34. Leaked iPhone 8 Dummies Feature Rear-Mounted Touch ID

  35. Leaked Molds Provide iPhone 8, 7s, and 7s Plus Size Comparison

  36. iPhone 8’s 3D Touch Tech Reportedly Costs 150% More Than iPhone 7s

  37. Latest iPhone 8 Dummy Model Backs up Previous Leaks

  38. New Apple Patents Show Embedded Touch ID, Edge-to-Edge Display

  39. LG Begins Manufacturing iPhone 8’s Revolutionary 3D Camera

  40. Multiple iPhone 8 Rumors Backed up by Leaked Video

  41. Analysts Claim Touch ID Won’t Be Embedded in iPhone 8’s Display

  42. September iPhone 8 Release Expected After Apple Resolves Production Issues

  43. iPhone 8 Rumored to Include AirPods and Feature ‘Enhanced’ Sound

  44. iPhone Sales ‘Pause’ Amid Anticipation for iPhone 8

  45. iPhone 8 Function Area: Here’s Everything We Know So Far

  46. Leaked iPhone 8 Case Might Prove Display-Embedded Touch ID Rumor

  47. New iPhone 8 Schematic Shows Wireless Charging Pad, No Rear Touch ID

  48. iPhone 8 Images Gallery

  49. Powermat CEO Calls Wireless Charging ‘Standard’ for iPhone 8

  50. Sketchy iPhone 8 Rumor Claims Only Two Models Will Be Released

  51. iPhone 8 Reported to Face ‘Severe Supply Shortages’ After Sept. Launch

  52. Alleged Foxconn iPhone 8 Dummy Backs up Design Rumors

  53. Unfortunate iPhone 8 Schematic with Rear Touch ID Leaks

  54. Apple Tests iPhone 8 Prototype with Touch ID Under Display, 4mm Bezels All Around

  55. Leaked iPhone 8 Schematic Validates Vertical Camera, Rear Touch ID Rumors

  56. More Evidence Points to iPhone 8 Rear-Mounted Touch ID Sensor

  57. iPhone 8 Expected to Be Delayed and Cost Less Than $1,000

  58. Exclusive ‘iPhone Edition’ Insider Information Leaked

  59. Report Suggests iPhone 8 Will Feature a ‘Water Drop’ Design

  60. Curved OLED iPhone 8 Display Rumored to Make a Comeback

  61. Samsung Casts Doubt on iPhone 8’s Embedded Touch ID Sensor

  62. iPhone 8 Rumored to Ditch Curved Display

  63. iPhone 8 Wireless Charging to Surge Supplier Revenue

  64. Apple Patent Hints at Advanced iPhone X 3D Facial Recognition

  65. Report Confirms 5.8″ OLED Display Destined for iPhone 8

  66. iPhone 8 with Revamped Touch ID Could Be Delayed

  67. iPhone 8 Will Fast Charge via Lightning, Not USB-C

  68. iPhone 8’s Entire Display Could Be a Fingerprint Scanner

  69. iPhone 8’s Stellar Battery Life Will Skyrocket Sales

  70. Revolutionary ‘iPhone X’ Selfie Camera Will Be Capable of Advanced 3D Facial and Iris Recognition

  71. iPhone 8’s 5.8-Inch Display Will Be Divided: 5.15-Inch Main Display with ‘Function Area’ Below

  72. Apple Courts Chinese Display-Maker to Supply OLED Panels for ‘Future iPhones’

  73. iPhone 8 Will Feature a Glass and Stainless Steel Chassis, iPhone 7s Won’t

  74. Apple Joins Wireless Power Consortium Further Hinting the iPhone 8 Will Feature Wireless Charging

  75. Samsung to Increase iPhone 8 OLED Display Production to 160 Million Units

  76. Rumor: Apple’s iPhone 8 Will Feature Wireless Charging Exclusively, Ship without 3.5mm Adapter

  77. Apple’s iPhone 8 Will Enter Production Ahead of Schedule This Year

  78. Apple’s iPhone 8 and Both iPhone 7s Models Will Allegedly Feature Wireless Charging

  79. iPhone 8 Rumored to Cost $1,000+, Nix Side Buttons, and Feature 3D-Sensing Technology, According to New Report

  80. Apple’s Switch to OLED Displays for iPhone 8 Could Cost $50 Million in Profits, Analyst Claims

  81. Apple’s OLED-equipped ‘iPhone 8’ Will Feature Advanced New 3D Touch, Siri Functionalities, According to Credible New Reports

  82. Taiwan-Based Lite-On Semiconductor to Provide Wireless Charging Parts for iPhone 8

  83. Could Apple’s iPhone 8 Feature a Laser-Guided Facial Recognition System? Well-Connected Analyst Says Yes

  84. Smartphone Makers Are Scrambling to Secure OLED Displays in the Wake of Apple’s Edge-to-Edge iPhone 8

  85. Apple’s iPhone 8 Will Be the Most Water-Resistant iPhone Ever

  86. iPhone 8’s Frame to Be Forged from Stainless Steel for Maximum Durability

  87. Next Generation Dual-Lens Camera with 3D Technology Could Be Coming to Apple’s iPhone 8

  88. Apple Is Currently Testing an iPhone 8 with Curved OLED Display Among 9 Other Prototypes

  89. Could Apple’s 4.7-inch iPhone Become the New Budget Offering?

  90. Why Apple’s Upcoming 5.8-inch iPhone 8 Will Be the Lineup’s ‘Crown Jewel’

  91. Rumor States Both 5.5-inch Versions of Apple’s iPhone 8 Will Feature Dual-lens Cameras

  92. Could This Be the iPhone 8? Here’s the Design and Features We Expect to See

  93. iPhone 8 Lineup Will Feature Larger Displays, Curved OLED Exclusive to iPhone 8 Plus, Credible Report Suggests

  94. New Rumor Suggests Apple Could Release a ‘Jet White’ iPhone 7 – But Don’t Hold Your Breath

  95. CEO of Sharp Display Co. Hints Apple’s iPhone 8 Will Feature OLED Display Technology

  96. iPhone 8 Expected to Be Available in 3 Sizes, Made of Glass, and Feature Wireless Charging

  97. Will Apple Launch a High-End Ceramic iPhone 8 Next Year? New Reports Suggest the Company Won’t

  98. iPhone 8 Could Boast a ‘Super Resolution’ Multi-Sensor Camera Unit, According to Apple’s Latest Patent Filing

  99. New Patent Suggests Apple’s iPhone 8 Will Receive the Major Redesign We’ve Been Waiting For

  100. Here Are 3 of the Internet’s Most Beautiful iPhone 8 Concepts