I would like to suggest you make yourself familiar with the basics first.

See this as an introduction: https://jazz.net/products/rational-team-concert/features/scm

In addition see http://pic.dhe.ibm.com/infocenter/clmhelp/v4r0/topic/com.ibm.team.scm.doc/topics/c_intro.html

Look into the tutorials from the help http://pic.dhe.ibm.com/infocenter/clmhelp/v4r0/topic/com.ibm.team.concert.dotnet.share.tutorial.doc/topics/rtc_share_tut_abstract.html

Scan some of the great articles about Jazz SCM: https://jazz.net/library/#tag=source%20control

You can basically compare repository workspaces and streams and that will tell you the differences. You can look at file histories to get more details.

If you have a change set you can accept it into a repository workspace for example from a work item. You can also search for change sets.