An electric charge is a physical property of matter that causes other matter to experience a force when placed in an electromagnetic field. It is determined by whether an object has more electrons than it should have or fewer electrons than it should have. An excess of electrons gives an item a negative charge, while a lack of electrons makes the charge positive.
When two objects with similar electric charges come near one another, their electromagnetic forces repel each other. Two objects in close proximity with opposite charges, on the other hand, experience a strong attraction. If the difference in their electrical charges is significant enough, they may experience an electrostatic discharge when they touch. This is the movement of electrons from the negatively charged object to the positively charged object, equalizing the charge between them.
Electric charge is also important to the generation of current. When electricity flows down a copper wire, it represents the movement of electrons from the negatively-charged end toward the positively-charged end. Electricity can also flow via charged ions in an electrolyte solution, such as the liquid or paste inside a battery cell. In either case, it is the difference in electrical charge that facilitates the flow of energy.