As cars have different uses, there are a lot of different tyres. You have different tyres for passenger cars, and if you have a sports car, as you will need a high performance tyre with a higher speed classification. The same way you will have different tyres if you have a SUV or a van. Here you need a higher load index and you might also want off-road properties.
If you have a light truck, you will need light truck tyres that are optimized for this. You will most probably want higher durability out of these tyres. If you have heavy machinery, you will need heavy tyres.
In addition to the different vehicles, you have different weathers, which means that you might need a set of both summer and winter tyres for these vehicles. A lot of different tyres exist for this reason.