OK, so imagine you are playing a game with your friends, and the game is called "rowing". In this game, you all sit in a long boat with oars and try to make the boat go as fast as possible by rowing in sync.
Now, varsity rowing is like the big leagues of this game. It's when you and your teammates from your school or college compete against other schools or colleges in a very important race called a "regatta".
Think of it like the Olympics of rowing, but just for college-level teams. The teams are made up of students who are really good at rowing and have spent a lot of time practicing and getting better.
During the regatta, the teams compete in different races, usually in different categories based on things like the size of the boat or the skill level of the rowers. The races are usually held on a river or a lake, and there are lots of people watching and cheering from the sidelines.
The goal of each team is to row as fast as possible and cross the finish line first. The team that wins the most races overall is considered the "champion" of the regatta.
So, to sum it up, varsity rowing is a fancy and competitive version of the game of rowing, where college-level teams race against each other in an important event called a "regatta".