What is version control?
Types of version control
Centralized vs. distributed. Why would you use either and which one do you use with Bitbucket?
DVCS workflows for Bitbucket Cloud
Whether you use Git or Mercurial, they both work with Bitbucket Cloud.
If you want to access Git repositories on Bitbucket, you need to install and set up Git first.
If you want to access Hg repositories on Bitbucket, you need to install and set up Mercurial first.