But what do you mean by brands??

Iphone is just only one ...from Apple, plain and simple.

Now if you mean the Iphone variations as 2G, 3G, 4, 4s 16/32/64 Gb; etc then you might as well go to apple site and look out for the reviews of the different devices and their specs.

Better read something and then comeback with actual and real concerns in the form of questions; otherwise people are just not going to respond.

regards!!