Ethernet cables are a type of networking cable used to connect devices like computers, routers, and switches in a local area network (LAN). They transmit data at high speeds, allowing for reliable internet connections and communication between devices. These cables come in various categories, such as Cat5e, Cat6, and Cat6a, each offering different performance levels. The higher the category number, the faster the data transfer rate and the greater the bandwidth. Ethernet cables typically have a standardized connector called an RJ45 plug, making them easy to use with most networking equipment.