the.com/chain of command

means The formal hierarchy through which orders flow down and accountability flows up, defining who reports to whom.

from Military in origin, built from two older words: 'chain' as a metaphor for linked, sequential connection (used this way since at least the 1700s), and 'command,' from Latin commandare, 'to entrust, order.' The phrase itself crystallized in military usage to describe the unbroken line of authority from the top officer down to the lowest rank — each link responsible for passing orders to the next. It migrated into corporate and bureaucratic speech in the 20th century as organizations borrowed military structure and vocabulary wholesale.