Synodality means that a group of people work together to make decisions. It's like when you and your friends want to decide what game to play. You all share your ideas and then together you choose the best game for everyone.
In the Catholic Church, synodality means that different people like leaders, priests, and regular church members work together to make decisions. They talk about important things like how to help poor people or how to make sure the church is doing a good job. Everyone gets to share their ideas and then they work together to find the best solution. This helps the church to be fair and inclusive, with everyone's voice heard.