The Town Council members are elderly characters from the episode "Plant It Now.Diglett Later" who run Diglett Village and serve as its local government. They founded the town themselves and have stuck around to keep things running.
The village relies on Diglett for farming, so when a band of thieves started stealing them, the Council called in backup—Team Rocket, Ash, and his friends. Turns out the "thieves" were actually the Council members' own kids from a nearby city, trying to scare their parents into retiring to a modern care facility. The plan didn't work out as intended.
With help from their unexpected allies, the Council members learned to fend off the trouble themselves. Grateful for the assist, they gave Ash's group a Silver Wing Badge and pointed them toward Silver Rock Isle.
The Town Council comes across as a hardworking, spirited bunch. They value their independence and aren't interested in giving it up—moving to that fancy retirement home was never going to happen, no matter how the kids tried. They'd rather stay active and useful in their own community.
Content compiled by AnimeList.moe from publicly available sources.