Equestrian is a sport that has people riding horses and competing in different events at the Summer Olympics. The person who rides the horse is called a "rider" and they work together with the horse to do some cool things like jumping over fences, riding in patterns, and even galloping around a big track.
There are three types of events in equestrian at the Olympics: dressage, jumping, and eventing. In dressage, the riders and horses work together to perform a routine that has specific moves and patterns. In jumping, the riders must guide their horses over a course that has a lot of big jumps, and the goal is to go through the course without knocking any of the poles down.
In eventing, the riders and horses compete in all three events - dressage, jumping, and cross-country. Cross-country is like a big obstacle course that the horse and rider have to go through, and they have to jump over some really challenging jumps.
Equestrian at the Olympics is really cool because the riders and horses have to work together and have a lot of trust in each other to be successful. It's not only about how well the rider can control the horse, but also about how well they can communicate and bond.