The maximum value that a function can attain is called the maxima of the function. The maximum value within a given range is called local maxima.
The minimum value that a function can attain is called its minima. The minimum value within a given range is called minima.
The concept of maxima and minima is used in various fields.
For eg- Suppose a scientist is working on a model where heat is generated. He'll find the function of heat generated with respect to temperature using the constraints given. Then the temperature corresponding to maximum or minimum heat generated can be found out using the concept of maxima and minima,