Created branch and how to move working copy to other branch

[prabhui]

HI Team

source tree , GIT Repository

I have created three different branches in GIT Repository (Master, Dev, QA )

MY local copy , i am working in Dev, if i modify any changes, i commited through source tree and pushed to Git repository , its working fine, 

I need to move the same changes from Dev to QA and Master.  How can i do that ?   can you please guide me

In my remote machine,   I created two different folder called "Dev" & QA" , i need to clone Dev repository files into  the "Dev folder and also QA repository files into QA folder.

how can i do that ?   Can you please guide me. thanks,

THnaks,

[Seth]

http://git-scm.com/book/en/v2

Pay attention 1.1-1.3, and Chapters 2 and 3.

The book describes command line operations, but the terminology matches SourceTree's buttons (e.g. instead of running "git fetch", hit the Fetch button).