Electric charge is a fundamental property of matter. All electric charge is carried by protons and electrons. Protons are said to have a charge of +1 electron unit, while electrons have a charge of −1. Protons are embedded inside atomic nuclei within atoms, they are not free to move like electrons. Therefore, when we talk about electric current, what we mean is the flow of electrons, and when we talk about static electricity, we generally mean an imbalance between negative and positive charges in objects, when a charge builds up in any object.
One common cause of static charge buildup is contact and friction between solid materials. When two objects are rubbed together static electricity is created – meaning, one object gives up electrons and becomes more positively charged while the other material collects electrons and becomes more negatively charged. (in dry weather, when you take off your shirt made of synthetic material, you can hear some tik-tik-tik noise just like if would hear if there was a short circuit in some system.
This is because one material has weakly bound electrons, and the other has many vacancies in its outer electron shells, so electrons can move from the former to the latter creating a charge imbalance after the materials are separated. Materials that can lose or gain electrons in this way are called