What is a fork, and how GitHub changed its meaning

Many distros also apply their own patches on top of Torvalds, perhaps sourcing them from the maintainers of drivers they need a bugfix for, or they maintain their own independent trees which periodically pull in lump sums of changes from other trees – meaning that the simple definition might not include the version of Linux which is installed on your computer, either. The design of GitHub’s fork and pull request model creates a cathedral that keeps people on their platform in a way that a bazaar would not. git request-pull prepares an email which will ask the recipient to fetch changes from a public repository and integrate them into their own branch.

Source: drewdevault.com