Okay kiddo, so imagine you're building a car out of LEGO bricks. You have a bunch of different pieces you can use: wheels, doors, windows, etc.
Now imagine you want to figure out some information about your car. Maybe you want to know how many wheels it has, or how many doors.
Multidimensional analysis is a way of looking at all the different pieces of information (or dimensions) that make up something, like your car.
So you might have a table that shows how many wheels and doors each car has. You could sort the table to show all the cars with four wheels and two doors, and see how many there are. Or you could group the cars by color, and see how many red cars have more than two doors.
You can do this kind of analysis with all sorts of things, not just cars. It's just a way of organizing and looking at different information all at once, so you can see patterns or relationships that you might not have noticed otherwise.