Explore the various types of roofs

These type of roof rails run parallel to the doors. Raised
rails has a gap between the roof and the rail where you can slide your hand in.

Flush roof rails run parallel to the doors like the raised
roof rails. However, in this type of rails, there is no gap between the roof
and the rail and you can’t slide your hand underneath.

These types of roofs have attachment points for roof racks
and these points are usually hidden by plastic covers or hidden under the
plastic trims.

Vehicles with bare roofs has no attachment for roof racks on them. With these kind of roofs, you can either install compatible roof rails first or use crossbars that can be mounted on the doors.