What's the Difference Between a Fork and Clone?
The concept of forking a project has existed for decades in free and open source software. To "fork" means to take a copy of the project, rename it, and start a new project and community around the copy. Those who fork a project rarely, if ever, contribute to the parent project again. It's the software equivalent of the Robert Frost poem: Two paths diverged in a codebase and I, I took the one less traveled by…and that has made all the difference.
There can be many reasons for a project fork. Perhaps the project has lain fallow for a while and someone wants to revive it. Perhaps the company that has underwritten the project has been acquired and the community is afraid that the new parent company may close the project. Or perhaps there's a schism within the community itself, where a portion of the community has decided to go a different direction with the project. Often a project fork is accompanied by a great deal of discussion and possibly also community strife. Whatever the reason, a project fork is the copying of a project with the purpose of creating a new and separate community around it.
Read more at OpenSource.com