A digital circuit is an electronic circuit that operates using discrete values, typically represented as binary numbers (0s and 1s). These circuits are fundamental in modern electronics, forming the basis for devices like computers, smartphones, and digital appliances. They use components such as transistors, logic gates, and flip-flops to process and store information. Digital circuits can be classified into two main types: combinational and sequential. Combinational circuits produce outputs based solely on current inputs, while sequential circuits consider past inputs and states, allowing for memory and feedback. This distinction enables complex operations and functionalities in various applications, from simple calculators to advanced microprocessors.