A voltage source is an electrical component that provides a constant voltage to a circuit. It can be a battery, a power supply, or any device that maintains a specific voltage level regardless of the current flowing through it. Voltage sources are essential in powering electronic devices and ensuring they operate correctly. There are two main types of voltage sources: ideal and real. An ideal voltage source maintains its voltage perfectly, while a real voltage source may have some internal resistance, causing the voltage to drop under load. Understanding these sources is crucial for designing and analyzing electrical circuits.