@Nakahara707
What @jpkarlsen said, but to answer your other question:
A mod is a fan-made modification to the game. Mods are not supported by EA/Maxis, but they do make it easy for you to use them. They range from really large and ambitious mods to small bugfixes and small corrections of things in the game that might annoy you.
I like mods and use them, but some mods do introduce new bugs into your game, so you want to evaluate which ones you use carefully. Also, if you have any other issues with your game the team here will (rightfully) ask you to test it without mods to confirm that it is, in fact, a game issue and not a mod issue. This is because the Team can't be held responsible for fixing code they didn't write; they can only fix their own code.
Also mods break every time there's a new patch and need to be updated regularly. So using them is a commitment to keeping them up to date so they don't mess up your game. What worked in a previous version might not work with a new patch, and since mods are completely fan-made the hard-working creators scramble each patch day.
I hope that answers your question!
