Amazon says:
The Netgear DS100 series of 10/100 Mbps dual-speed hubs connects multiple PCs to share printers, files, Internet access, and e-mail communications. One can mix and match 10 and 100 Mbps PCs, servers, and peripherals with these hubs, all without any configuration required. The DS100 family combines many capabilities in little space, and the units are designed for price-conscious small-business owners. One can connect 10 or 100 Mbps network devices to the hub. Each port individually senses and adjusts to run at the proper speed.

Each unit has a built-in self-learning bridge that provides the communications link between the 10 and 100 Mbps network devices. The intelligent bridge automatically manages network traffic so that 10 Mbps traffic and 100 Mbps traffic do not crowd each other's segments.