Git TagGit tag is nothing but a marker or symbol for a point in time snapshot of your git repository.
There are two types of tags in git:
Lightweight TagA pointer to a specific commit. It only has a tag name.
In addition to putting a marker on a specific commit, git physically create the snapshot of all files and keep it internally with a tag message, email, and a date.
To create a tag for a given commit, the command syntax is:
git tag tag_name commit_id
To push the tag to the remote repository
git push remote_name tag_name
Release is a concept of github, it internally uses git tag to create a static point of time snapshot. The details can be found at https://help.github.com/articles/creating-releases/.
Releases can be created on:
Current head of master or branches
Recent past commits.