Wheel collider
A specialized collider that models a vehicle wheel as a downward raycast rather than a rolling cylinder.
Simulating a tyre as a true rigid cylinder rolling on the ground is both expensive and unstable — contact gets lumpy and grip is hard to tune. A wheel collider cheats: from the wheel's suspension mount a ray is cast straight down, the hit point gives the spring's compression, and a friction model derives longitudinal and lateral forces from the wheel's slip.
Unity's WheelCollider made the pattern widely known, but the same idea drives most arcade-leaning driving games. It gives stable contact at speed and full control over grip and drift, at the cost of physical fidelity — a raycast vehicle doesn't feel a kerb as honestly as a real cylinder would.