You would also need to enable mods through the options menu in The Sims 4 game. But the general idea is that you download the file(s) and place those into your Mods folder (Documents/Electronic Arts/The Sims 4/Mods). Most mod creators have included clear instructions on how to install their mods. I would definitely play the game without custom content but never without mods. Mods are what give the game so much depth and possibilities. I personally think The Sims 4 wouldn’t be as successful as it is without mods and custom content but especially mods. The best part is that mods are created by the players, who actually play and enjoy the game. Simply put, mods add features or can change the functions in the game. According to The Sims 4 Wiki: Mods are modifications to the game that affect visual and/or functional elements.