In the old days if you wanted to use the version control software Git with a SHA-256 hash function, rather than broken SHA-1, you were stuck using it locally. This posed a major problem, as Git repositories are meant to be shared, adapted, and changed by many! Even though we should have moved away from SHA-1 years ago Github, Gitlab, Bitbucket and many others had a monopoly on the hash function you choose, but now sha2git.com is a safe haven for SHA-2 repositories allowing the users to share code without broken hash functions.
Great! I want to use SHA-2 git will all my new git repositories. Time to switch!