A livery company is like a club for people who have similar jobs or interests. It's like a group of friends who all work in the same field or enjoy the same hobbies.
But it's not just any group - these clubs have been around for hundreds of years! They started in London, England in medieval times when people who made things like clothes, or sold them, wanted to make sure they were doing a good job and not being cheated by other vendors.
Nowadays, livery companies are like big families that support each other and help people in their professions. They often have fancy dinners where members dress up in special clothes, and they might give out awards to people who do a really good job at their work.
So, if you ever become a tailor, or a brewer, or a scientist, or any other profession, you might want to look into joining a livery company!