Reels for bass fishing rods are spinning reels and baitcaster reels and vary in speed (amount of line per rotation) and line capacity (amount of line).
Reels are important for:
Drag: Drag is a friction setting on the reel that sets the level the bass pulls on the line (or a snag) to which the friction is overcome and the reel rotates letting line out and preventing the line from breaking. Setting the drag factors include: