There are a few different ways to carry skis and snowboards on your vehicle to get them to the mountain. The simplest racks will consist of clamps that attach to the front and rear cross-bars on your vehicle and grip the skis or boards with soft rubber pads.
Different racks have various mounting hardware options to attach to different crossbar styles. Other racks will use an existing hitch or trunk mounted bike rack you may have, and carry the skis vertically in the same kind of rubber padded clamps. Another common option is to use a roof mounted cargo box. These come in various shapes and sizes, some designed specifically to work well with especially long skis.