A node B is like a really important stop on a road trip. It's a place where lots of information passes through (like cars on a road).
Imagine you're playing a game with your friends online. You all connect to the game through the internet, but the information needs to pass through lots of different places (like buildings or traffic lights) to get from your computer to where the game is hosted. One of those places might be a node B.
A node B is like a traffic controller for information. It sits between your computer and the game, making sure that the data is sent and received correctly. It's kind of like a huge switchboard that connects lots of different wires together.
So, if you're playing a game and something goes wrong, it might be because of a problem with the node B. But don't worry, because the experts who look after the node B are really good at fixing things quickly!