To archive the repository without including versioning information, you can use the git archive command; there are many output formats but the classic one is the .zip one:

$ git archive master --format=zip --output=../repoBackup.zip 

Please note that using this command is not the same as backing up folders in a filesystem; as you will have noticed, the git archive command can produce archives in a smarter way, including only files in a branch or even in a single commit; for example, by doing this you are archiving only the last commit:

$ git archive HEAD --format=zip --output=../headBackup.zip 

Archiving files in this way can be useful if you have to share your code with people that don't have Git installed.