Let's take a comparative look and see if they're the same here:
Grass
Attacking
2x damage: Water, Ground, Rock, Magic, Time
1/2 damage: Grass, Poison, Flying, Bug, Fire, Steel, Dragon
0x damage: N/A
Defending
2x damage: Flying, Poison, Fire, Bug, Ice
1/2 damage: Grass, Water, Ground, Magic...