Which of the following correctly describes the function of the 'IN' operator?

The 'IN' operator is used in various programming and query languages, including SQL, to test whether a specified value matches any value within a defined list of values. This function is particularly useful when you want to filter data based on a set of possible values. For instance, if you have a database of cities and you want to find records for specific cities, you can use the 'IN' operator to specify the cities of interest. This allows for concise and readable code, especially when dealing with multiple potential matches.

In contrast, checking numbers within a range pertains more to operators like BETWEEN or comparison operators. Finding the maximum value involves aggregate functions such as MAX, while calculating averages is associated with the AVG function. Each of these operations serves a different purpose, highlighting why the query related to checking for membership in a list accurately describes the role of the 'IN' operator.