Definition
Active Process
An active process is a process that currently resides in main memory (RAM) and is competing for or utilizing system resources (CPU, I/O). In the context of the Seven-State Process Model, active processes are those in the Ready, Running, or Blocked states.
Active processes are distinguished from suspended processes, which have been swapped out to secondary storage to free up available physical memory.
Management
The number of active processes that can be maintained simultaneously is limited by the available physical memory. If too many processes become active, the system may experience thrashing, leading the operating system to perform swapping to maintain performance.