The difference between processes, procedures and tasks
A procedure is a synonym for a task, but a process is an upper level series of major steps, with those major steps being procedures or tasks. Tasks are made up of actions or steps.
A process is an upper level description of a series of major steps required to accomplish an objective. Processes are generally made up of procedures or tasks. A task is another way of describing a procedure. Another way of putting it is that a process is a sequence of tasks.
DITA does not distinguish between processes and tasks, although DITA 1.2 does provide strict task and general task variants of the task information type.
The term task is used in DITA, in preference to procedure, work instruction or unit rule. A task topic contains one procedure or task, and is made up of a series of steps. In turn, steps are made up of commands (or actions), step results, and perhaps substeps.
In a process, each step outlines the result or outcome of a task, and that step is typically linked to the task topic that details that step at a lower level.