ELI5: Explain Like I'm 5

Graded vector space

All right kiddo, imagine you have a bunch of boxes that you can arrange in a line. Now, each box can have something inside it, like a toy or a candy. But here's the catch, each box can only hold things of a certain size.

Let's say the first box can hold small toys like marbles or lego bricks, while the second box can hold bigger toys like stuffed animals or action figures. The third box can hold even bigger toys like bikes or scooters, and so on.

This is kind of like a graded vector space. A vector space is a bunch of mathematical objects (called vectors) that can be added together and multiplied by numbers. But in a graded vector space, each element (vector) has a certain "size" or "degree" assigned to it, just like the boxes we talked about.

In a graded vector space, you can add and multiply vectors just like in a regular vector space, but you also have to pay attention to their sizes. You can only add vectors of the same size, and you can multiply a vector by a number of any size.

So, let's say you have a graded vector space where the first degree elements are like the small toys in our boxes, and the second degree elements are like the big toys. If you want to add two vectors of the first degree, you can do that no problem. But if you try to add a first degree vector with a second degree vector, it won't work because they're different sizes.

But you could multiply a first degree vector by a number of any size, like 2 or 5 or even 0.5, and you'd get another first degree vector of the same size. Similarly, you could multiply a second degree vector by a number of any size, and you'd get another second degree vector of the same size.

So that's the basic idea of a graded vector space. It's just like a regular vector space, but with different "sizes" assigned to each element. And just like with the boxes, we have to be careful about which sizes we can add together, and which sizes we can multiply by numbers.