Whenever your Zap successfully automates something, it's called a task. Trigger steps do not count as tasks, but successful action steps do. A single Zap can generate one or more tasks, depending on how many Action steps it has. You can see all your tasks in Task History.
If you have a Zap set up to send you a text message every time someone completes a transaction in your online store, that text message counts as a task. If you want to send a text message and also add a row to a spreadsheet, the text message and the spreadsheet row both count as tasks.