Okay, keep in mind that this is "mom" level knowledge (as in, my kids know this, and I think this is what I've heard them say?)
Each pokemon has one or two types that they are, but they also each have 2 or 3 or 4 attacks that they know how to do, and those attacks also have types, that may or may not match the type of the pokemon.
For instance: say you have a charmander. It's a fire type pokemon. It knows Scratch, a normal type attack, and Ember, a fire type attack. If it's fighting a grass type pokemon, it should use Ember, because grass type pokemon are vulnerable to fire type attacks. If the grass type pokemon somehow learned Bubblebeam, a water type attack, it still might beat the charmander, because the fire type pokemon is vulnerable to water type attacks. The fire type attack is strong against the grass type pokemon; the grass type pokemon is vulnerable to the fire type attack. The fire type pokemon is vulnerable to water type attacks; water type attacks are strong against fire type pokemon.
OTOH, fire type attacks are, I think, weak against water type pokemon; water type pokemon are resistant to fire type attacks. But a grass type pokemon who knows a water type attack, even though their attack is strong against fire type pokemon, is still vulnerable to fire type attacks.
no subject
Each pokemon has one or two types that they are, but they also each have 2 or 3 or 4 attacks that they know how to do, and those attacks also have types, that may or may not match the type of the pokemon.
For instance: say you have a charmander. It's a fire type pokemon. It knows Scratch, a normal type attack, and Ember, a fire type attack. If it's fighting a grass type pokemon, it should use Ember, because grass type pokemon are vulnerable to fire type attacks. If the grass type pokemon somehow learned Bubblebeam, a water type attack, it still might beat the charmander, because the fire type pokemon is vulnerable to water type attacks. The fire type attack is strong against the grass type pokemon; the grass type pokemon is vulnerable to the fire type attack. The fire type pokemon is vulnerable to water type attacks; water type attacks are strong against fire type pokemon.
OTOH, fire type attacks are, I think, weak against water type pokemon; water type pokemon are resistant to fire type attacks. But a grass type pokemon who knows a water type attack, even though their attack is strong against fire type pokemon, is still vulnerable to fire type attacks.
Don't know if this helps....