Just a mod question.

[Cyotey]

I've downloaded mods for Skyrim and know how to do that with the help of a friend. However, I have not downloaded mods from Steam workshop. How exactly does this work? Thanks for the feedback :)

[Stark Raven]

The Workshop works like a manual installation for Skyrim, but with different file types and in different locations, and it does its work automatically. Essentially what it does is download .vpk files from the Workshop database to a folder called Steam\steamapps\common\left 4 dead 2\left4dead2\addons\workshop. The addons folder is where you put manually downloaded L4D2 mods.
There is a file in the left4dead2 folder called the addonlist.txt, this controls mod load order and listing. It will update automatically when your game loads.

Please note that the Workshop is not as reliable as manually downloading, and you will lose your mods if you're not online.