Minecraft Forge is a mod that acts as a manager of mods, which allows you to easily install many mods, simply installing all the mods in your mods folder, there are many mod creators, who design their mods to be compatible with Minecraft Forge, thanks to its manager advantage and compatibility with the different mods that are designed for Minecraft Forge

How to download and install Minecraft Forge for Minecraft 1.12.2

1- Download Minecraft Forge 1.12.2
2- Double click on the downloaded file (you can also click on the secondary file, open with and select Java program)
3- Select install client and accept
4- You will already have installed the Forge 1.12.2

Download Minecraft Forge for Minecraft 1.12.2