Fundamentally it is a same as git: you can push, pull, you have commits, branches, merges, etc... and branching is easy.
It is mostly a difference in philosophy. While git will leave you with lots of powerful and flexible tools, Mercurial will be much more limited out of the box, advanced features are extensions you have to enable.
The Mercurial history is also considered sacred, and everything is done do discourage you from modifying it, commands like squash and rebase are hidden behind extensions, branches are also permanently attached to commits (the equivalent of git branches exist and are called bookmarks).
There is also no staging area. Instead of "remote" branches, there is a simpler "phase" system that tell you which commits are local and which one have been pushed.
All that makes Mercurial easier to use, especially for non-developers. And in fact, most people who tried both preferred it over git, with the exception of git experts, who prefer git for its speed and flexibility.
tbh I'm mostly happy with git. It does what I need it to do. Yes, it could be easier and more transparent, but everything is a trade-off.