A current source is an electronic device that delivers a constant flow of electric current to a circuit, regardless of the voltage across it. This is essential in various applications, such as powering sensors or maintaining stable conditions in electronic circuits. Current sources can be found in both analog and digital forms, and they are often used in conjunction with other components like resistors and capacitors. In practical terms, a current source can be implemented using transistors or operational amplifiers. It is crucial in ensuring that devices like LEDs or microcontrollers receive the appropriate amount of current for optimal performance. By providing a steady current, these sources help prevent damage and ensure reliable operation in electronic systems.