Difference between Jailbreaking/Unlocking

The is huge difference between unlocking and jailbreaking your iPhone.
Jailbreaking is to allow your iPhone to use thrird party programs
(100% legal). Unlocking at the other hand is to allow your iPhone
device to use SIM cards from different providers. Unlocking at the
other hand is a little controversial of whether it is legal or not. If
you use the unlocking for personal reasons and use and not for
commercial gain then it is legal.

Why you should unlock your iPhone:

Unlocking an iPhone device sometimes may be inevitable. The iPhone
works in a certain way with the SIM cards. Users connect to the
network using GSM and certain crucial info that SIM card holds. iPhone
is build in that way that when you buy it it stays linked with the
specific GSM network of the SIM card (of a specific provider). That
means that if for some reason you want to change the SIM card
(travelling to a foreign country) iPhone will not allow that.

Pros and Cons of iPhone Unlocking:

The positive side of unlocking we explained it at the upper paragraph.
Of course there should be a negative too. Apple does not approve the
unlocking of your device so if you be "caught" with a unlocked iPhone
they will not accept the warranty of your device, so if any hardware
problems occurs then you are on your own. Another major problem is in
the App store and in the updates of your iPhone's software. You will
propably find in front of you many problems.

How to unlock it in general:

The steps are very simple but I will not explain them in this article.

   * Download a specific software
   * You transfer it to your iPhone
   * Follow simple steps to unlock it

As a final solution you can always pay a visit to an expert!