Static Guard is a product that protects a person from the effects of static electricity. Static electricity is an electrical charge that simply does not move as opposed to the normal type of electrical charge that flows from place to place. Static electricity has no current to follow so it simply does not move. Static electricity can build up when an object that does not conduct electricity well (something like rubber or plastic) is touched with or rubbed against something that does conduct electricity well (something like clothing). The resulting static electricity can result in a person getting a shock when they touch a piece of clothing or something else that static electricity has built up on.
Static Guard is a spray coating that neutralizes the charge of static electricity. It is a mixture of water, with the minerals and salts removed, and alcohol. When a person sprays Static Guard on her clothing what she is spraying is essentially molecules that are good at conducting electricity. These molecules are have both a positive charge and a negative charge, which prevents static electricity from building up because the neutrally charged static particles have no place to go. Once something has been sprayed with Static Guard even rubbing something that conducts electricity against it will not result in a build up of static electricity like it normally would.
There are a number of variations on the Static Guard concept. As opposed to a spray solution, certain brands of washing machine detergent solutions can have the same qualities of Static Guard. When clothes are washed with these detergents, the fibers that make them up are allowed to hold in more water and moisture than they normally would. This makes them more capable of conducting electricity than they normally would be, which in turn prevents the build up of static electricity much the same way that spraying them with Static Guard would.