Okay kiddo, imagine you're playing a game where you're pretending to be a bird flying around the Earth. Now, imagine you're not flying exactly around the Earth, but you're kind of stuck in one spot, always following the Earth's path but never really getting too close or too far away. That's what a quasi-satellite is!
A quasi-satellite is an object that kind of looks like a satellite because it's always in the same general area as the Earth as it moves through space, but it's not really going around the Earth in a full circle like a regular satellite would. Instead, it's kind of just floating there, always following the Earth's path but not really getting too close or too far away.
Scientists study quasi-satellites because they can help us understand how objects move around in space, and they may also have some practical uses in the future. But for now, just remember that a quasi-satellite is kind of like a pretend satellite that's always hanging around the Earth, but not really going all the way around it. Cool, huh?