A non-contract iPhone (in the US at least) costs typcally $450 more than it's contract counterpart. The benfit is that with out a contract, you are not obliged to hold onto that same phone for 2 years (mostly), and if you want to upgrade before your contracat expires, you have to pay an annoying fee to get out of your contract.
An iPhone 4 is an iPhone.....
the difference is 0.0.1
the difference between a iphone 4 and iphone 5 is that the back is made out of aluminium and it has 5 row of apps on a page
it's just color difference
The iPhone 2G is much slower than the iPhone 3G.
temporary/contract work
If you mean IPhone 4S the difference is that 4S has Siri, which is like a voice assistant on your phone.
The iPhone 4 has reception issues and the iphone 3 dosn't
The Work on some Different Carriers.
"Contract of sell" is just "contract of sale" misspelled.
A key difference between an iPhone 5C and an iPhone 5 is the support for more 4G LTE frequency bands by iPhone 5C.
Difference between Percentage of Completion method and Completed Contract method?