I am going to apologise in advance for this question, i just cant get my head around the answers.

1. what is the difference between jailbraking and unlocking the iphone?
2. i have an iphone that is working (i can make and recieve calls etc) with a t-mobile sim in the UK, can i update to the new firmware 1.1.1 and the phone will still work.

once again sorry for the question but i just do not understand the answer i have read.
is there a guide for thick heads like me?

thank you