You can probably distinguish between iPhone, iPod touch and iPad. But it gets more difficult to differentiate between the different generations of the device. And even within the same device it is sometimes important to know what bootrom version you have.
Visual differences
iPad
The iPad 1 has rounder edges, lacks a camera, and is notably thicker than all future models. The iPad 2 is lighter and thinner than the iPad 3, which is the only retina iPad that has the old 30-pin adapter. The iPad 4 is the first iPad to ship with the Lightning adapter and can be distinguished as such. The iPad mini is, of course, much smaller. Check the model number just to be sure.
iPhone
The first generation iPhone (sometimes called 2G version) can be detected by the two colors (plastic and metal) on the back side.
The iPhone 4 and iPhone 4S can be clearly detected by the metal frame on the outer edges. The 4S additionally has a line above the mute switch. The 3G and 3GS are pretty similar from the outside and have a rounded back. The iPhone 5 is higher than the iPhone 4 and the side is no longer metal, but black or white.
iPod touch
The first generation iPod touch has round edges, but a flat backside. Newer models (2nd, 3rd, 4th generation) have a slightly round backside (not completely flat). The iPod touch 5 is completely flat, much like the iPhone 5, and comes in a variety of colors and has a wristband slot.
Model numbers
You can see the model number in Settings, General, About, Model. The model number has a two-letter code, a number and some more letters. The last part stands for the country/region
[1]. The first letter can be "F" (refurbished), "M" (normal retail), or "P" (personalized / engraved). For example MC605B is the model MC605 and B is for the region
[1].
- MA501 PA501 FA501 iPhone 2G black 4GB
- MA712 PA712 FA712 iPhone 2G black 8GB
- MB384 PB384 FB384 iPhone 2G black 16GB
- MB046 PB046 FB046 iPhone 3G black 8GB A
- MB489 PB489 FB489 iPhone 3G black 8GB B
- MB702 PB702 FB702 iPhone 3G black 8GB C
- MC176 PC176 FC176 iPhone 3G black 8GB D
- MB048 PB048 FB048 iPhone 3G black 16GB A
- MB496 PB496 FB496 iPhone 3G black 16GB B
- MB704 PB704 FB704 iPhone 3G black 16GB C
- MB499 PB499 FB499 iPhone 3G white 16GB A
- MB500 PB500 FB500 iPhone 3G white 16GB B
- MB501 PB501 FB501 iPhone 3G white 16GB C
- MB632 PB632 FB632 iPhone 3G white 16GB D
- MB705 PB705 FB705 iPhone 3G white 16GB E
- MB715 PB715 FB715 iPhone 3GS black 16GB old bootrom
- MB735 PB735 FB735 iPhone 3GS black 16GB old bootrom
- MC135 PC135 FC135 iPhone 3GS black 16GB old bootrom
- MB717 PB717 FB717 iPhone 3GS black 32GB old bootrom
- MB737 PB737 FB737 iPhone 3GS black 32GB old bootrom
- MB716 PB716 FB716 iPhone 3GS white 16GB old bootrom
- MB736 PB736 FB736 iPhone 3GS white 16GB old bootrom
- MC136 PC136 FC136 iPhone 3GS white 16GB old bootrom
- MB718 PB718 FB718 iPhone 3GS white 32GB old bootrom
- MB738 PB738 FB738 iPhone 3GS white 32GB old bootrom
- MC555 PC555 FC555 iPhone 3GS black 8GB new bootrom
- MC640 PC640 FC640 iPhone 3GS black 8GB new bootrom
- MB715 PB715 FB715 iPhone 3GS black 16GB new bootrom
- MC131 PC131 FC131 iPhone 3GS black 16GB new bootrom
- MC135 PC135 FC135 iPhone 3GS black 16GB new bootrom
- MB717 PB717 FB717 iPhone 3GS black 32GB new bootrom
- MC133 PC133 FC133 iPhone 3GS black 32GB new bootrom
- MC137 PC137 FC137 iPhone 3GS black 32GB new bootrom
- MC132 PC132 FC132 iPhone 3GS white 16GB new bootrom
- MC136 PC136 FC136 iPhone 3GS white 16GB new bootrom
- MC134 PC134 FC134 iPhone 3GS white 32GB new bootrom
- MC138 PC138 FC138 iPhone 3GS white 32GB new bootrom
- MD126 PD126 FD126 iPhone 4 GSM black 8GB A
- MD128 PD128 FD128 iPhone 4 GSM black 8GB B
- MC318 PC318 FC318 iPhone 4 GSM black 16GB A
- MC603 PC603 FC603 iPhone 4 GSM black 16GB B
- MC608 PC608 FC608 iPhone 4 GSM black 16GB C
- MC319 PC319 FC319 iPhone 4 GSM black 32GB A
- MC605 PC605 FC605 iPhone 4 GSM black 32GB B
- MC610 PC610 FC610 iPhone 4 GSM black 32GB C
- MD196 PD196 FD196 iPhone 4 GSM white 8GB A
- MD198 PD198 FD198 iPhone 4 GSM white 8GB B
- MC604 PC604 FC604 iPhone 4 GSM white 16GB
- MC606 PC606 FC606 iPhone 4 GSM white 32GB
- MD146 PD146 FD146 iPhone 4 CDMA black 8GB
- MC676 PC676 FC676 iPhone 4 CDMA black 16GB
- MC678 PC678 FC678 iPhone 4 CDMA black 32GB
- MD200 PD200 FD200 iPhone 4 CDMA white 8GB
- MC677 PC677 FC677 iPhone 4 CDMA white 16GB
- MC679 PC679 FC679 iPhone 4 CDMA white 32GB
- MC918 PC918 FC918 iPhone 4S black 16GB A
- MD234 PD234 FD234 iPhone 4S black 16GB B
- MD235 PD235 FD235 iPhone 4S black 16GB C
- MD276 PD276 FD276 iPhone 4S black 16GB D
- MD377 PD377 FD377 iPhone 4S black 16GB E
- MC919 PC919 FC919 iPhone 4S black 32GB A
- MC923 PC923 FC923 iPhone 4S black 32GB B
- MD241 PD241 FD241 iPhone 4S black 32GB C
- MD278 PD278 FD278 iPhone 4S black 32GB D
- MD379 PD379 FD379 iPhone 4S black 32GB E
- MD257 PD257 FD257 iPhone 4S black 64GB A
- MD258 PD258 FD258 iPhone 4S black 64GB B
- MD269 PD269 FD269 iPhone 4S black 64GB C
- MD280 PD280 FD280 iPhone 4S black 64GB D
- MD381 PD381 FD381 iPhone 4S black 64GB E
- MC920 PC920 FC920 iPhone 4S white 16GB A
- MD237 PD237 FD237 iPhone 4S white 16GB B
- MD277 PD277 FD277 iPhone 4S white 16GB C
- MD378 PD378 FD378 iPhone 4S white 16GB D
- MC921 PC921 FC921 iPhone 4S white 32GB A
- MD244 PD244 FD244 iPhone 4S white 32GB B
- MD279 PD279 FD279 iPhone 4S white 32GB C
- MD380 PD380 FD380 iPhone 4S white 32GB D
- MD260 PD260 FD260 iPhone 4S white 64GB A
- MD271 PD271 FD271 iPhone 4S white 64GB B
- MD281 PD281 FD281 iPhone 4S white 64GB C
- MD382 PD382 FD382 iPhone 4S white 64GB D
- MA623 PA623 FA623 iPod touch 1G black 8GB A
- MA624 PA624 FA624 iPod touch 1G black 8GB B
- MA839 PA839 FA839 iPod touch 1G black 8GB C
- MA627 PA627 FA627 iPod touch 1G black 16GB A
- MA628 PA628 FA628 iPod touch 1G black 16GB B
- MB376 PB376 FB376 iPod touch 1G black 32GB
- MB525 PB525 FB525 iPod touch 2G black 8GB old bootrom
- MB528 PB528 FB528 iPod touch 2G black 8GB old bootrom
- MB529 PB529 FB529 iPod touch 2G black 8GB old bootrom
- MB531 PB531 FB531 iPod touch 2G black 16GB old bootrom
- MB532 PB532 FB532 iPod touch 2G black 16GB old bootrom
- MB533 PB533 FB533 iPod touch 2G black 32GB old bootrom
- MB534 PB534 FB534 iPod touch 2G black 32GB old bootrom
- MC086 PC086 FC086 iPod touch 2G black 8GB new bootrom
- MC008 PC008 FC008 iPod touch 3G black 32GB
- MC011 PC011 FC011 iPod touch 3G black 64GB
- MC540 PC540 FC540 iPod touch 4G black 8GB
- MC544 PC544 FC544 iPod touch 4G black 32GB
- MC547 PC547 FC547 iPod touch 4G black 64GB
- MD057 PD057 FD057 iPod touch 4G white 8GB
- MD058 PD058 FD058 iPod touch 4G white 32GB
- MD059 PD059 FD059 iPod touch 4G white 64GB
- MB292 PB292 FB292 iPad 1 WiFi black 16GB
- MB293 PB293 FB293 iPad 1 WiFi black 32GB
- MB294 PB294 FB294 iPad 1 WiFi black 64GB
- MC349 PC349 FC349 iPad 1 GSM black 16GB
- MC496 PC496 FC496 iPad 1 GSM black 32GB
- MC497 PC497 FC497 iPad 1 GSM black 64GB
- MC769 PC769 FC769 iPad 2 WiFi black 16GB
- MC770 PC770 FC770 iPad 2 WiFi black 32GB
- MC916 PC916 FC916 iPad 2 WiFi black 64GB
- MC979 PC979 FC979 iPad 2 WiFi white 16GB
- MC980 PC980 FC980 iPad 2 WiFi white 32GB
- MC981 PC981 FC981 iPad 2 WiFi white 64GB
- MC773 PC773 FC773 iPad 2 GSM black 16GB
- MC774 PC774 FC774 iPad 2 GSM black 32GB
- MC775 PC775 FC775 iPad 2 GSM black 64GB
- MC982 PC982 FC982 iPad 2 GSM white 16GB
- MC983 PC983 FC983 iPad 2 GSM white 32GB
- MC984 PC984 FC984 iPad 2 GSM white 64GB
- MC755 PC755 FC755 iPad 2 CDMA black 16GB
- MC763 PC763 FC763 iPad 2 CDMA black 32GB
- MC764 PC764 FC764 iPad 2 CDMA black 64GB
- MC985 PC985 FC985 iPad 2 CDMA white 16GB
- MC986 PC986 FC986 iPad 2 CDMA white 32GB
- MC987 PC987 FC987 iPad 2 CDMA white 64GB
- MC954 PC954 FC954 iPad 2 R2 black 16GB
- MC989 PC989 FC989 iPad 2 R2 white 16GB
- MC705 PC705 FC705 iPad 3 WiFi black 16GB
- MC706 PC706 FC706 iPad 3 WiFi black 32GB
- MC707 PC707 FC707 iPad 3 WiFi black 64GB
- MD328 PD328 FD328 iPad 3 WiFi white 16GB
- MD329 PD329 FD329 iPad 3 WiFi white 32GB
- MD330 PD330 FD330 iPad 3 WiFi white 64GB
- MC733 PC733 FC733 iPad 3 CDMA black 16GB
- MC744 PC744 FC744 iPad 3 CDMA black 32GB
- MC756 PC756 FC756 iPad 3 CDMA black 64GB
- MD363 PD363 FD363 iPad 3 CDMA white 16GB
- MD364 PD364 FD364 iPad 3 CDMA white 32GB
- MD365 PD365 FD365 iPad 3 CDMA white 64GB
- MD366 PD366 FD366 iPad 3 Global black 16GB
- MD367 PD367 FD367 iPad 3 Global black 32GB
- MD368 PD368 FD368 iPad 3 Global black 64GB
- MD369 PD369 FD369 iPad 3 Global white 16GB
- MD370 PD370 FD370 iPad 3 Global white 32GB
- MD371 PD371 FD371 iPad 3 Global white 64GB
- MC572 PC572 FC572 Apple TV 2G black 8GB
- MD199 PD199 FD199 Apple TV 3G black 8GB
Another three types of model numbers:
- A1203 iPhone1,1 m68ap iPhone 2G
- A1241 iPhone1,2 n82ap iPhone 3G
- A1303 iPhone2,1 n88ap iPhone 3GS
- A1332 iPhone3,1 n90ap iPhone 4 GSM
- A1349 iPhone3,3 n92ap iPhone 4 CDMA
- A1387 iPhone4,1 n94ap iPhone 4S
- A1213 iPod1,1 n45ap iPod touch 1G
- A1288 iPod2,1 n72ap iPod touch 2G
- A1318 iPod3,1 n18ap iPod touch 3G
- A1367 iPod4,1 n81ap iPod touch 4G
- A1219 iPad1,1 k48ap iPad 1 WiFi
- A1337 iPad1,1 k48ap iPad 1 GSM
- A1395 iPad2,1 k93ap iPad 2 WiFi
- A1396 iPad2,2 k94ap iPad 2 GSM
- A1397 iPad2,3 k95ap iPad 2 CDMA
- A? iPad2,4 k93aap iPad 2 R2
- A1416 iPad3,1 j1ap iPad 3 WiFi
- A1403 iPad3,2 j2ap iPad 3 CDMA
- A1430 iPad3,3 j2aap iPad 3 Global
- A1378 AppleTV2,1 k66ap Apple TV 2G
- A1427 AppleTV3,1 j33ap Apple TV 3G
(to be finished)
For an up to date list, please see the iphonewiki:
http://theiphonewiki.com/wiki/index.php?title=Models