The Meta section is for questions about this website. Questions about Pokemon go here:
https://pokemondb.net/pokebase/ask
Also this is not a full answer, but a wall is a Pokemon that can get hit by lots of attacks without fainting. They often have some kind of healing, like 50% healing moves, leftovers, or regenerator. When an opponent can't defeat a wall, he/she/they/it usually switches out, which gives the wall an opportunity to use utility moves like stealth rock or U-turn.