Do you need minecraft in order to get any minecraft mod or the mod is the total game free?

Do you need minecraft in order to get any minecraft mod or the mod is the total game free?

Added (1). like is it separate

All Minecraft mods require that you own Minecraft. They are mods. Not ROM hacks

You need the original files in order to modify them. The mod does not contain the whole game. If you get a copy of minecraft, you will probably need to watch a video on youtube to understand how to mod the game.