[paulddraper]

Correct.

One is refs/heads/<name> and the other is refs/tags/<name>

Branches are expected to change. When a commit is authored, HEAD (the current branch) updates to that commit.

Tags are expected not to change (though they can).

[lucasoshiro]

Other difference (actually, more like a consequence of what you said) is that Git keeps reflogs for branches but not for tags