The unit is
1. The name of the standard quantity for measuring things. For example, meters are units for measuring length, kilograms are units for measuring mass, and they are units for measuring volume.
2. refers to organs, organizations, etc. Or a department belonging to an organ, organization, etc. : directly under ~. Subordinate ~ career ~. There are many people taking part in the competition.
A standard for calculating the number of things. For example, "meter" is the unit for measuring length, "second" is the unit for calculating time, "gram" is the unit for calculating weight or mass, and so on. A subordinate organ, group or department. Chapter 18 of Liu Qing's Iron Wall: "The sunset glow is full of prisoners handed over by various units." What is the "original guide": "I think this is probably the work unit of old Joe."