how to tag a project in git code example

Example 1: git push tags

#from git 1.8.3 you can use
git push --follow-tags
#single tag push
git push origin 
#All tags (if possible use --follow-tags 'cause it's safer)
git push --tags

Example 2: git add tag

git tag -a v1.2 
git push origin v1.2

Example 3: git tag a previous commit

git tag -a v1.2 9fceb02 -m "Message here"