what's the difference between a parallel cable and a usb cable?

USB also lets you connect your camera to the computer while it is already running, unlike Parallel.

With USB you can add up to 255 devices, but you have to have a port for each.  They are easy and cheap to add.  For more information on USB:

http://www.lvr.com/usbc.htm

For scanning, USB has been on par with SCSI scanners!

The cables themselves use different connectors -- you cannot interchange them without getting the soldering gun out.

The two connections are really quite different at every level.  Parallel ports go back to the first PCs and provided faster transfer rates than serial ports because the data was sent 8 bits at a time (in parallel) rather than 1 bit after the other (serially).  A serial cable therefore has 8 wires for data plus some others for grounding, clock, etc while a serial cable can get by with as little as two (one data and one ground if you only want to send data in one direction).

USB (Universial Serial Bus) is an improvement on the original RS-232C serial port in that it is MUCH faster.  Also, multiple serial devices can share the same bus by being "daisy chained".  That is one device plugs into the computer, the next device plugs into that device, etc.  In practice, however, this is generally limited because the bus can only supply power for limited number of devices.  Also, Windows has been programmed to automatically detect when devices are added or removed from the bus.  That makes it especially useful for devices like digital cameras that may only be connected to the computer long enough to download pictures to the hard drive.

Finally, as GivenRandy points out, you can't mix and match as the cables for USB and parallel use completely different connections.  There are, however, converters that will allow you to connect different kinds of devices to the various kinds of ports.  For example, Belden makes a parallel to USB converter (and software drivers) that allows parallel port printers to be connected to a USB port on a computer.  I don't know of anyone who would support a digital camera USB connection to a parallel port.  For more information on those kinds of products, you might try: http://www.usbstuff.com/

Good luck.

Adjusted points from 50 to 75

Thank you all. I'm going to award points to all 3 of you. This information will help me quite a bit. It won't however help me sell the camera to the person who was wanting it. She said that she needs the usb cable for her setup and the camera comes with the parallel cable. Oh well that what I get for trying to be in business on the web. You all might check out my site at http://www.cheapskatesave.com I've some great prices on all kind of electronics there.
Please no more comments to this question from ther than the three that have already responded. Thanks again.

Community Support has reduced points from 75 to 25

Hello everyone,

I am reducing the points on this question to 25.

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