A circuit is a closed path in which charges flow through continuously. Circuits are intriguing and exciting to learn because the idea of circuits operates all around us. From charging laptops to fans, the idea of circuits literally powers everything around us. To first understand circuits, we need to understand the functions of charges. As often heard in magnetism, opposite poles attract, while like poles repel. The same idea applies to electricity where there are two types of electric charges, being positive and negative. Cool Right! This implies a relationship between electricity and magnetism, which we will not discuss here, but is something that might be fascinating. In the case of electricity, opposite charges attract and as charges repel. Electrons are an example of negative charges, while protons are an example of positive charges. Now, electrons are the charges that usually flow through circuits. You may ask why electrons and not protons. And the answer to that is that electrons are relatively easy to transfer between objects as electrons are located on the outer parts of the atom. Protons, on the other hand, are located in the nucleus of the atom, meaning that only in very specific cases, usually requiring nuclear energy, would protons be able to leave the nucleus.

In reality, electrons flow in circuits, but the standard that is widely used is that of conventional currents where protons are tracked. This standard was set due to Benjamin Franklin who did not have the same level of information about atoms and charges that we do now, and therefore Franklin thought that positive charges traveled around in circuits, when in reality it is the negative charges that travel in circuits. Since it is the standard, the conventional current will be used to explain the concept of a circuit. A circuit requires three things to be maintained. There must be a conducting path, a complete path, and a source of voltage. Typically, the conducting path are wires, the source of voltage is a battery, and the complete path is just the circuit having a closed path. The concepts of voltage, current, and resistance will build off these requirements and will be explored in part 2 of the exploration of circuits.