HUB

HUBs: the foundational layer for network connectivity, enabling shared communication across multiple devices.

A HUB operates as a central connection point for devices in a local area network (LAN), broadcasting incoming data packets to all connected ports. This means every device on the HUB sees all network traffic, simplifying network setup but increasing collision domains and overall network congestion. Primarily used in older Ethernet networks (e.g., 10BASE-T), HUBs are largely replaced by switches today due to their inefficiency in modern, high-bandwidth environments. For example, connecting five PCs to a HUB means each PC shares the total bandwidth, unlike a switch which provides dedicated bandwidth per port.

https://www.cisco.com/c/en/us/products/switches/hubs/index.html