What is the source supposed to do

what is the source supposed to do

which source?

the source on github website for unreal engine 4

generally there are two ways to get and use UE4 .
1- getting compiled version from launcher
2- getting none compiled version(source) from github which you have to compile it yourself.

when you have ue4 source you can customize it (adding new features, fixing problems).

thank you, but now how to make compiling for the none compiled versions