clr == clear all; close all; clc;

clr clears your workspace and command window, so you can start fresh.

clr performs: clear all; close all; clc;

This clears your workspace, closes all figures, and clears command window.

clr is a quick way to "reset" Matlab.

The only point of this function is to save key strokes. If you use Matlab often and you value your time, then this function may appeal to you.