Differentials are one of the most important elements of your vehicle. The unit allows wheels to rotate at varying speeds, thus allowing the car to corner correctly. If your inner and outer wheel are both moving the same speed, cornering will be difficult and not as smooth as you would like it to be.
There are three main types of differential in modern vehicles: open, limited-slip, and torque-vectoring. Each setup has its own benefits. While open differentials are the oldest and most reliable kind, they are unsuited for performance or off-road vehicles that need unique abilities to handle their specific job.