Here's why:
* Party Limits: Each game has a set limit on how many Pokémon you can have in your active party (usually 6).
* Full Party: When your party is full, you cannot catch any more Pokémon.
* Options: If you encounter a Pokémon you want to catch, you have these options:
* Release a Pokémon: You can release one of your current Pokémon to free up a slot.
* Store a Pokémon: You can deposit a Pokémon in a Pokémon Box (like the PC in your house) to free up a slot.
* Catch and Release: You can catch the new Pokémon and then immediately release it (if you don't want to keep it).
Let me know if you have any other Pokémon questions!