A parameter is a limit or boundary that defines what's possible or acceptable in a given situation. If your teacher says you can write a book report on any novel within certain parameters, she might mean it must be at least 100 pages long, published after 1950, and appropriate for your grade level. Those requirements are the parameters of the assignment.

In mathematics and science, parameters are values or variables that help define a problem or system. When a computer programmer writes code, she sets parameters to control how the program behaves: maybe a game character can jump between 2 and 8 feet high, and those numbers are parameters that shape the game experience.

Think of parameters as the playing field or framework for whatever you're doing. When planning a class party, your parameters might include the budget ($50), the time (one hour), and the space (your classroom). These parameters don't tell you exactly what to do, but they establish the boundaries within which you can be creative.