What does the nice value mean in process priority management in Linux?

The nice value in Linux determines the process priority in CPU scheduling. It sets the 'friendliness' of the process to others — the higher the nice value (from -20 to 19), the lower the process priority and the less CPU it receives. The default value is 0. For example, a process with nice=10 will receive less CPU time than a process with nice=0, which is useful for background tasks so they do not interfere with more important ones.