Oh, sorry! :-/

I feel bad so I'll make up for it a bit.

"Weight" is how much something is pulled down by the Earth's gravity.

"Mass" is how much "physical stuff" is in a thing.

Why are there two different words?

Well, an object has the same mass everywhere, but the weight changes depending on where it is.

For example, a soccer ball might weigh a pound, but if you put it under water, it will try to rise so it has a negative weight under water - but exactly the same mass.

And of course in orbit, everything has a zero weight, but the same mass.

For most of history, people didn't understand the difference. Newton was the one who figured it out.

And "volume" is literally just the size of an object.

For example, if I have cube that is 1 meter by 1 meter by 1 meter, it has a volume of 1 cubic meter.

If I fill that cube with water, it will weigh about 1 ton, and mass about the same.

If I fill that cube with air, it will mass about a kilo - a couple of pounds - but it will weigh nothing.

Sorry again for being rude!