What's the difference between Mercurial's "tip" tag and the "default" branch

Question

We are just switching to Mercurial where I work this week. I'm starting to read material, and was hoping somebody could succinctly answer this question:

What's the difference between Mercurial's "tip" tag and the "default" branch?

Solution

Tip is the most recent changeset in the repository. Default is a branch. Tip is a special Tag (a named changeset) which always refers to the most recently changed Head.

Comments

[Jonathan Hartley]

So does this mean that tip will move around from one branch to another as people push changesets on different branches? If so, what's the point of it, since you can't rely on it being in any one place? Thanks!

[Dave Horton]

True, I can't think of any usecases for Tip aside from checking how old my repo is or sharing the id of my tip when talking with other developers. Also as giszmo points out, hg update -r tip is a quick way to get to the newest code regardless of branch.

[dwardu]

tip is just an alias for the last changeset in your repo. Sometimes it comes in handy, e.g. you make a change in branch supercalifragilisticexpialidocious which you would then like to merge into branch default; so then you update to branch default and because you know that the work you want to merge into default is at the tip of your local repository (because you’ve just committed it), instead of doing hg merge supercalifragilisticexpialidocious you may do hg merge tip.

[Admin]

note to future readers: "somewhat" is a a placeholder here for a tag or branch name. It is not a special branch, tag, term, or keyword in mercurial, like I originally thought.