All Under One Banner

Have you ever seen a big group of people wearing the same t-shirts and cheering together? That's kind of like the "all under one banner" idea. It means a bunch of different groups of people coming together to work towards a common goal or idea. It's like when you and your friends all play together to win a game. Everybody works together and supports each other to reach the same goal. It's like a big team where everyone has their own skills and strengths, but they all work together towards a common goal.