Radar homing is generally categorized by how the target is "illuminated" (lit up with radio waves) and where the receiver is located.
The missile only has a receiver. It depends on a external radar source —typically from the launching aircraft or a ground station—to illuminate the target. Radar Homing Guidance for Tactical Missiles
The missile carries its own radar transmitter and receiver. Once the target is within range, the missile "goes active," allowing it to operate as a "fire-and-forget" weapon. Radar homing is generally categorized by how the
Radar homing guidance is a sophisticated technology that allows tactical missiles to track and intercept targets by sensing reflected or emitted radio frequency (RF) energy. By housing the seeker system directly on the missile, these weapons achieve high precision, even against maneuvering targets. The missile carries its own radar transmitter and receiver
To ensure a successful hit, the missile uses a feedback loop to constantly adjust its flight path.
Radar Homing Guidance for Tactical Missiles - Springer Nature
The missile tracks RF emissions actually coming from the target, such as its own radar or communication signals. This is common in "anti-radiation" missiles. The Guidance Loop & Control