SHA512 is a hash function in the SHA2 family.
Like SHA256, it’s often used to check the the integrity of large or important file transfers over a network. The provider of the file can provide a SHA512 of the file to be transfered, and the person who downloads the file can then check that they recieved the file without corruption.
On linux you can use sha512sum:
On OSX you can use shasum:
shasum -a 512 example.txt