A cost that remains unchanged in total despite variations in volume of activity within a relevant range is a

That's called a fixed cost. Examples of fixed cost include salaries, rent, maintenance, etc. In a nutshell, any cost the company incurs irrespective of what the extent of operations is. The opposite type is variable cost, which will increase or decrease depending on the activity level. Both fixed and variable costs make up the total cost of the firm.

A cost that remains unchanged in total despite variations in the volume of activity within a relevant range is a fixed cost. The fixed cost is a type of cost behavior which remains unchanged regardless of the unit or activity changes in a production process. There are four types of cost behavior, which are the fixed cost, the variable cost, the mixed cost, and the step cost.