About XI fundamentals

Hi Experts,

I am new to XI, i have one doubt on connectivity of existing integration.

1. I read somewhere that XI connects to existing integration solutions

through JMS and SOAP messaging, is it so.....?

2. What is JMS and SOAP messages, what is the functionality of these messages ?

3. How to integrate to existing intergration solutions using these messages??

please reply me as soon as possible,

thanx,

murali.