Process

A process is an instance of a running program, with its own memory space, its own copy of the environment it inherited, and a numeric identity. Processes form a tree: each is spawned by a parent and can outlive it.

Working with them from a script has a few sharp edges.

Names are not what you think. The process name is the executable's name, which can differ from an application's display name — commonly by capitalisation. A pattern matching the wrong one silently matches nothing, and a command that reports "stopped" without having stopped anything is worse than an error, because the next step proceeds on a false premise.

Substring matching is dangerous. A pattern intended for one program matches any command line containing it, including unrelated system processes whose names happen to include the substring. Matching the executable exactly is the safe form.

Something may restart it. A process under a supervisor comes back immediately when killed, so "stop" and "kill" are different operations: a clean quit exits successfully and stays down, while a signal looks like a crash and triggers a restart.

Diagnosing contention needs per-process detail rather than an aggregate load figure, which lags and never says which program is responsible. See Resource Starvation.