UE4 equivalent to unity packages?

hey, so just another guy transferring from unity.
main ?:
what is the ue4 == of .unitypackage
I am running the engine on a Compaq cq60 laptop,
so my ability to even use the engine is hindered.

the reason I ask is that I cannot use something like google drive to hold the project,
so I need a neat way of updating files with my other collaborators.

----some info on project----
the main issues we have had were simple,
but in unity there would never be a fix.

  1. no splitscreen audio
  2. too many realtime lights(lights could be shot/destroyed. ambient light was zero)
  3. too many (semi?) active rigidbodies(almost the entire map was destroyable.)

I ported to ue4 because:

  1. issue 1 auto fixed
  2. ue has beefier graphics(higher bottom line but better speed I HOPE)
  3. same as above for physics I suppose?
    again if I am wrong about anything on that list, please be sure to let me know.