Pokéball-
A pokéball is a round object. Colored white and red, a Pokéball
is used for capturing pokemon. Once caught, a trainer can keep the Pokemon
he/she has acquired inside the ball.
However,
the trainer can only hold 6 pokemon at a time. The rest are kept where
the trainer got their pokédex. (i.e Ash gets his stored pokemon
from Professor Oak.)
Evolution- Almost every pokémon can evolve. Evolution of Pokémon is changing into another form when a pokemon has gained enough levels required. For example, a Charmander can evolve into Charmeleon and Charizard.
GYM- Almost every gym is inhabited by a gym leader. The gym is owned by the trainer and when a challenger comes along, the trainer must accept his challenge. The fight takes place on the gym's battlegrounds.
GYM Leader- Each gym leader has its own gym, where challenges come in and out to fight. If the challenger is able to beat the gym leader, the challenging trainer will receive a gym badge. These badges are required for entering the pokemon league.
Badge- A badge is what you receive from GYM trainers. If you collect them all, you can participate in the Pokemon League festivities.
Pokémon
Center- The place for healing pokémon.
If your pokemon is injured or hungry, this is the place to go.