filter: Program used in between two programs. Receives and modifies input information provided by one program and sends the results to another program.

finc: Fast incremental backup. Command used to selectively copy an entire file system to tape.

rtpi value: Real-time priority value. Process with a priority value between 0 and n, with n being the highest priority value assigned by the system. The process with the highest rtpi value will run before all other processes except system class processes.