What is the difference between PPK and RTK mode and how to choose?

Real-Time Kinematic (RTK)and Post-Processed Kinematic (PPK) are both centimeter-level positioning systems; RTK is recommended when users have high requirements for convenience and real-time operation, and there is a network communication link in the survey area. If the user does not require real-time performance or is in an environment with a poor network communication, then the PPK post-processing method can be used.