Originally posted by Mr.SeriousCatt:

Speaking of mods, if we use them, do we need to have them installed? do the game download them for us when I try to enter a world with mods? I doubt the mods are server side and is not needed to download.

Most mods are client-side, and will need to be installed by you. There are "Mod Managers" to ease this process (I recommend r2modman), but they're not required. Almost all mods use the BepInEx plugin.