All chefs learn about it early in their training; they also know it as the browning reaction.
If you are planning to make a full-flavored French stew, known as either beef bourguignon or beef in burgundy, your first instructions are to brown the meat, a messy and time-consuming step. You may choose to ignore this step and just dump the raw beef chunks into the stewing liquid. This shortcut may save you time, but the flavors enhanced by the browning reaction will never be activated. Your great French stew will likely taste flat and lifeless.