There are three common options. The first, as featured in our #1 product on this list is a tension mount. They attach to your vehicle with hooks and use some sort of padded mount to rest against the rear of your vehicle.
These are great and usually affordable. But if you have heavy bikes or more than two, that’s about their limit.
Second is a hitch mount. Hitch mounts are sturdy by the nature that they’re attached to your frame. There are no hooks and everything tends to be a full metal design. So you won’t have to worry about a bumpy road or anything like that.
Their limitations are that they can be quite obtrusive, and you need to get one installed if you don’t have it. Some people don’t like the idea of having a bike jutting out from the rear of their vehicle. Especially in parking situations.
Lastly, is a roof mount setup. If you don’t want to worry about a bike on the back of your SUV then mounting it on the roof is another proper solution. But if you drive anywhere with low clearances you’ll have to be mindful, and it’s not as easy to access your bike when you have to get it off the roof!
For each option there are pros and cons.