A mole in espionage means a secret spy who works for one country or organization but pretends to be a part of another country or organization. Imagine a teddy bear sneaking into another kid's house to learn their secrets and report them back to their own group. That's what a mole does - sneaks around, collects information, and sends it back to their own group.
Moles are really sneaky, so they can work for years without being discovered. They might even get important jobs in the organization they're spying on, so they can learn more about what's going on. It's like being a secret agent, but instead of fighting bad guys, you're pretending to be their friend and collecting information.
Sometimes, if a mole is caught, they can be in big trouble! But other times, they might be able to switch sides and help the people they were spying on. So, in a way, moles can be heroes or villains, depending on how you look at it.
Overall, being a mole is very sneaky and secretive, and it takes a lot of skill and bravery to pull it off!