It makes magic happen!
If you're wondering what in the name of Cuthulu is CrackMapExec, here's a quick summary:
It's a post-exploitation tool (e.g. Veil-Pillage, smbexec)
It's meant to be the 'glue' between exploitation frameworks when pentesting Active Directory
It's fully concurrent: you're able to connect, authenticate etc.. to multiple hosts at the same time
It has an internal database which is used to store credentials and track users with Administrative privileges
It's functionality is based on several other tools and libraries (a list of them are in the Github repo's README)
It's opsec safe: everything is either run in memory, enumerated over the network using WinAPI calls or executed using built-in windows tools/features.