Whether you’re an international spy with a new mission or a high school student with math homework — when you get an assignment, you’d better do it! An assignment is a task that someone in authority has asked you to do.
The word assignment is just the noun form of the common verb assign, which you use when you want to give someone a duty or a job. When you assign something, that something is called an assignment. The word can also refer to the act of distributing something. If you are distributing new office furniture at work, you might say, “Assignment of the new chairs will begin tomorrow.”