Answer Description
A HUB forwards all packets out all interfaces, except the one the packet was received on. This means information sent from Host A to Host B, is very easily intercepted by Host C. Even if Host C wasn't addressed in the data header. A HUB is considered a layer 1 (Physical Layer) device in the OSI Model.
Wikipedia
An Ethernet hub, active hub, network hub, repeater hub, multiport repeater, or simply hub is a network hardware device for connecting multiple Ethernet devices together and making them act as a single network segment It has multiple input/output (I/O) ports, in which a signal introduced at the input of any port appears at the output of every port except the original incoming A hub works at the physical layer (layer 1) of the OSI model A repeater hub also participates in collision detection, forwarding a jam signal to all ports if it detects a collision In addition to standard 8P8C ("RJ45") ports, some hubs may also come with a BNC or an Attachment Unit Interface (AUI) connector to allow connection to legacy 10BASE2 or 10BASE5 network segments
Ethernet_hub - Wikipedia, the free encyclopedia