Hey there!
Aweh, I won't scold you my friend, everyone starts somewhere, don't feel intimidated to ask me anything. :)
As Quakkz said above, it's basically Pokemon that use the same type moves. *Example: Charizard using Flamethrower* Because Charzard is using a fire move and he himself is a fire pokemon, he gets what we call "Stab" stab increases the strength of the move by 50%. This can also stack with abilities, such as adaptability, and set up moves, such as swords dance.
So if you're ever in a battle with a player, you have no super effective moves and your other moves do neutral damage, ALWAYS go for the move that shares your Pokemon's type, as it will do the most damage. :)
I hope I was able to help, if you need any more assistance regarding this topic or anything else, send me a PM and I'll gladly help you out. Or just post down below! Any is fine really. :)
*NOTE: Stab works the same with dual type Pokemon, so: Charizard is a Flying/Fire Pokemon, he WILL get stab to any flying type move and fire type move.
wow, thanks a lot.. :D and how if my pokemon is a dual-type one? does both of them counts? i mean let's take Charizard as example which is fire and flying type. Will fire moves and flying moves get the STAB effect?