There's a lot of different kinds. But they're all pretty simple and can be explained rather easy.
A ratio and a proportion are really the same thing but in different ways. For example, say I have two lines. A big line and a small line. The big line is 10 feet tall, and the little line is 5 feet tall. We can say they are proportionate to each other because they have a ratio of 10/5 which can be simplified to 2.They are proportionate and the taller line is 2 times higher.
I hope this makes sense.