Fabric is the "modern" Minecraft modding software that is very modular.
We use Fabric in this guide so install it by going to https://fabricmc.net/use/ Download the .jar or .exe and run it.
Below is a list of performance and utility mods to make your Minecraft experience better and most importantly smooth.
The list is in order of most importance and they all work together including what they do with why to use them.