What Does Serializer/Deserializer (SerDes) Mean?
A serializer/deserializer (SerDes) is an integrated circuit or device used in high-speed communications for converting between serial data and parallel interfaces in both directions. A SerDes is used in a variety of applications and technologies, where its primary purpose is to provide data transmission over a single or differential line by minimizing the number of I/O pins and connections. In short, it converts parallel data into serial data so that they can travel over media that does not support parallel data or it is used in order to save bandwidth.
Techopedia Explains Serializer/Deserializer (SerDes)
A SerDes chip facilitates the transmission between two points that use parallel data over serial streams, reducing the number of data paths required for the transmission. This lowers the number of required connecting pins, so wires and connectors can be kept small and thin. On the transmitter side, parallel data are converted to serial data, whereas on the receiver side the opposite happens. Most SerDes devices are fully capable of full-duplex operation, so conversion of data takes place in both directions simultaneously. SerDes chips are used in wireless routers, gigabit Ethernet systems, storage applications and fiber optic communication systems.