What does vendor mean in web file structure?
Solution 1:
It's a common convention to put files coming from various third party sources (the "vendors") in a folder named that way.
You can use it as it makes it clearer what's "from the project" and what is a dependency you rely upon, but it is merely a convention, not an obligation.
Solution 2:
/vendor usually refers to a directory that contains third party plugins.
Solution 3:
Most if the time, there are 3rd party libs stored and commonly it's ignored in VCS.