Firewire (IEEE 1394) and USB (Universal Serial Bus) are two separate high-speed bus technologies that allow multiple devices to be connected to a computer. The two technologies are not integrated, and it is not possible to connect a USB device to a Firewire port either directly. A Firewire to USB adapter cable for transferring digital video (DV) is available from at least one manufacturer, but it can be expensive and difficult to find.
Even if you don't have a Firewire to USB adapter cable, it doesn't mean that your Firewire devices are useless if you have a USB port, or vice versa. Several companies do provide dual Firewire/USB hubs. This type of device has two ports in a single hub, which may be either external or internal; one port is used Firewire and one for USB, allowing either type of device to function. The combination hub is actually two separate ports combined into a single form factor for convenience; there is no conversion between Firewire and USB taking place when you use one of these hubs.

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The Universal Serial Bus (USB) is a standard for peripheral devices. It began development in 1994 by a group of seven companies: Compaq, DEC, IBM, Intel, Microsoft, NEC and Nortel. USB was intended to make it fundamentally easier to connect external devices to PCs by replacing the multitude of connectors at the back of PCs, addressing the usability issues of existing interfaces, and simplifying software configuration of all devices connected to USB, as well as permitting greater bandwidths for external devices.

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