*** the best overall reference on cabling is the wonderful site

*** the standard - TIA/EIA-568-A has been superceded by TIA/EIA-568-B and it describes all Cabling Categories.  It should be on  but isn't

*** also see Cable Standards and Cable Glossary

*** see also - awesome cable site !!

A cable is simply a wire, or fiber that either supplies power, or carries information from point A to point B.  Cables can be metallic or optical.  There are thousands of standards and types of cables.  Here we will concentrate on the Telecom cables (coax, twisted pair, etc), described by the TIA 568-B standards.  

Note on Connectors - of course, for every cable, there are at least two connectors, and each connector has both a physical interface and an electrical interface standard.- but I'll cover the "connectors" elsewhere.

To do justice to this section I recommend investing in a few books on the subject.  But for starters, here is an excellent guide entitled Wire, Cable, and Fiber Optics, written by Steve Lampen.  In addition, BICSI has a few training manuals for both residential and telecom cabling which are worthy investments.