[PAR_WIG1350]

The least flexible form of swerve has all wheels linked for both steering and drive either physically or in code. This is often referred to as crab drive.

The next level adds to this by separating the drive control to drive the left and right sides separately while steering the front and back wheels separately.

Both of these are often hybridized by adding skid steering to the maneuvers available to the drivers which allows for pivoting. However if swerve drive is pushed to its full potential this becomes unnecessary. By steering and driving each module independently the robot becomes physically capable of rotation about any given point with the robot at any given angle as well as linear translation at any given angle. The only limiting factor with such a layout is in the software used to coordinate the modules.

In other words, swerve drive is an incredibly diverse family of drive trains, but the number of wheels used has less of an effect on the characteristics of the drive train than how they are linked together does.