What is the relationship between unity of command and chain of command?

Unity of command refers to The principle that no subordinate in an organization should report to more than one boss whereas a chain of command refers to A system whereby authority passes down from the top through a series of executive positions or military ranks in which each is accountable to the one directly superior.

The two are moreless the same they work to eliminate confusion that can arise in an organisation when their is lack of clear leadership structures.