A decoder is an electronic device or circuit that converts encoded data back into its original format. It is commonly used in communication systems to interpret signals, such as those found in digital television or radio broadcasts. Decoders help ensure that the information transmitted is accurately received and understood by the intended device or user. In computing, decoders play a crucial role in processing instructions within a CPU (Central Processing Unit). They translate binary code into signals that control various components of the computer, enabling it to perform tasks. This process is essential for the smooth operation of software applications and overall system functionality.