All flows (inflows and outflows) in pure cash / bank (online) has to be tracked and monitored minutely. This is critical as all cash has to be brought into the system immediately and effectively without incurring must cost. This function is critical as if not monitored carefully, it may lead to higher costs and even penalties by authorities if not controlled and guided properly.
The treasury function is concerned with management of funds at the micro level. Since funds or cash is the lubricant of all business activity, availability of funds on day-to-day basis is to be ensured by the treasury manager.
The treasury function is thus complimenting to the finance function in general.