Digital circuits are electronic circuits that operate using discrete values, typically represented as binary numbers (0s and 1s). They are the foundation of modern electronics, enabling devices like computers, smartphones, and digital cameras to process and store information. Digital circuits use logic gates, which perform basic operations such as AND, OR, and NOT, to manipulate these binary values. These circuits can be categorized into combinational and sequential circuits. Combinational circuits produce outputs based solely on current inputs, while sequential circuits consider past inputs and states, allowing for memory and timing functions. Together, they form the backbone of complex systems in computer architecture and embedded systems.