Okay kiddo, so you know how when you go to another country, you need a passport and sometimes a special visa to say that you're allowed to be there? Well, there are people called consuls who help make sure everything goes smoothly for people traveling between countries.
A consular corps is like a group of consuls who work together in the same place, like a city or country. They help people from their own country who are traveling in the other country by giving them advice, helping them get visas, and giving them emergency help if something goes wrong.
But consuls don't just help people who are traveling. They also help build good relationships between their countries by meeting with other people in the host country's government and talking about things like trade and cultural exchange. They also make sure that citizens of their own country who live in the host country are treated fairly and have access to the same rights as everyone else.
So in short, a consular corps is a group of consuls who work together to help their citizens who are traveling or living in another country, and to build good relationships between their own country and the host country.