Imagine you live in a world that's only two-dimensional, like a piece of paper. You can move forwards, backwards, left and right, but you can't move up or down because there's no third dimension. Now imagine you live in a world that's three-dimensional, like the world we live in. You can move forwards, backwards, left and right, up and down because there's the third dimension.
Well, seven-dimensional space is a world that has seven dimensions instead of just three or two. That means you can move in seven different directions, not just left, right, forward, backward, up, and down. It's hard to imagine what this would look like since we're used to living in a three-dimensional world.
Think of it like a game of chess. A chessboard is two-dimensional because the pieces can only move along the x and y axis. But if you had a chess game with pieces that could move in seven different directions, that would be like existing in a seven-dimensional world.
Scientists use the concept of seven-dimensional space to explain complex math problems and theoretical physics. But for us as regular folks, it's just fun to imagine what it could be like to exist in a world with seven dimensions.