A drum beat is what you hear when someone is playing a drum. It's like a pattern of sounds the drum makes over and over again. It's kind of like a dance that the drum is doing with your ears.
So imagine you're tapping your foot on the ground while your friend plays the drum. If your friend keeps playing the same sounds over and over again, that's the drum beat. It's like a musical rhythm that helps everyone in the band or the audience know when to play or clap along.
Drum beats can vary a lot depending on the kind of music being played. Some might be fast and exciting, like you're running really fast. Some might be slow and relaxed, like you're lying in a hammock on a sunny day.
Sometimes people will make up their own drum beats or change them around to make the music more interesting. But usually the drummer will keep playing the same beat so that everyone can stay in time and enjoy the music together.