What is the allosteric site?

Every enzyme has an active site which is the site where the substrate binds in order to activate the enzyme, the allosteric site is somewhere other than an active site. When a molecule binds to the allosteric site it changes the confirmation of the active site. The binding onto the allosteric site may have a inhibitory or stimulatory effect

A site that allows molecules to activate or inhibit enzyme activity.

The allosteric site is an area on an enzyme where inhibitors or activators may bind, changing the shape of the enzyme and therefore influencing the rate of reaction - this is NOT the active site.