Data transmission refers to the process of sending and receiving digital information between devices. This can occur over various mediums, such as cables, wireless signals, or optical fibers. The data is typically encoded into binary format, allowing it to be transmitted efficiently and accurately. There are different methods of data transmission, including serial and parallel transmission. In serial transmission, data bits are sent one after another over a single channel, while in parallel transmission, multiple bits are sent simultaneously across multiple channels. Each method has its advantages and is used based on the requirements of the communication system.