RAISED RAILS/ RAISED SIDE RAILS
Running from front to back, this railing, located on the roof of your vehicle, has space between it and the roof. (You can likely fit your hand under it).
Like the raised rail, the flush rail runs from the front to the back of the vehicle. They are considered flush as there is no space between the car and the rail.
Small holes (usually 4), perhaps hiding under little tabs, found either along the inside of a flush rail or on the top of the roof itself. These holes provide a fixed point where roof rack towers/feet can be attached.
A part of the roof rack. The cross bars attach to the top of the towers. The fit kit attaches underneath the towers. The towers hold the cross bars up.
Square, round or “airplane winged” in shape, the cross bar attaches to feet/siderails and spans across the roof, right to left, usually door frame to door frame.
The fit kit allows for the towers to attach to the car. Typically consists of four clips and four pads, specifically designed for the roof line of your vehicle. A fixed point or flush railing fitkit may consist of screw or clamps, to fit into the fixed point or grab the flush railing.
The part that grabs/touches/pressure fits to the door frame.
The rubber part that makes direct contact with the roof of the vehicle. The pad is attached to the bottom of the foot/tower.