D-Link DSC-100 - Manual (Page 4)

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Introduction to USB
USB stands for Universal Serial Bus. It is a standard for
connecting external devices to your computer quickly and easily. One of
the nice things about USB is that power can be provided to the USB
device through the USB cable. Some devices such as printer need more
power than the USB ports can provide, so those devices will have to use
an external power source. USB also allows the device to be connected
and removed from the PC without the need to shut down the computer.
Currently many USB products are widely available on the market
and more are being developed for future release. Because of the high
speed of the USB interface, a USB hub can be used to connect more
than one USB device to one USB port at one time. The USB standard
specifies that up to 127 devices can be connected to your computer.
USB is fast enough for webcams and other video devices to
transfer large amounts of data. The USB specification allows for two
different speeds. A lower speed of 1.5Mbps (Megabits per second) is
used in low-power and low-speed devices. The faster speed of 12Mbps
is used for most devices, especially USB audio and video devices.
The current standard for USB is version 1.1. A new version called
USB version 2.0 will be much faster at 400Mbps and will replace
version 1.1 as the standard for the market in the near future. This device
will still be compatible with the new USB 2.0 standard when it becomes
available.