Electrical signals are variations in electric current or voltage that carry information. They are fundamental to the functioning of many devices, including computers, smartphones, and communication systems. These signals can be analog, which vary continuously, or digital, which represent data in discrete values, typically as binary code. In biological systems, electrical signals are crucial for communication between cells. For example, in the human body, neurons transmit signals through action potentials, allowing for rapid communication within the nervous system. This process is essential for reflexes, muscle movement, and overall coordination of bodily functions.