Short for Category 5, Cat5 cable is network cabling that consists of four twisted pairs of copper wire terminated by RJ45 connectors. Cat 5 cabling supports frequencies up to 100 MHz and speeds up to 1000 Mbps. It can be used for ATM, token ring, 1000Base-T, 100Base-T, and 10Base-T networking. Cat 5e cable runs should be limited to a maximum length of 328 feet (100 meters)

Currently Cat5e has replaced Cat5 as the industry standard for data cablimg communication and is rated up to 350 Mhz. Computers hooked up to a LAN are connected using Cat 5e cables, so if you're on a LAN, most likely the cable running out of the back of your PC is Category 5.Cat5e cable is known as a twisted pair cable and comes in either solid or stranded types. Solid CAT5e cable supports long cable runs and is designed for fixed cabling situations like homes, offices, and buildings. Stranded CAT 5 cable is more pliable and better suited for shorter-distances. Stranded CAT5 cable is commonly used for patch cables or crossover cables.
Cat 5 is based on the EIA/TIA 568 Commercial Building Telecommunications Wiring Standard developed by the Electronics Industries Association as requested by the Computer Communications Industry Association in 1985.Cat5e Plenum A type of inside cable intended for use in plenums. While plenums are convenient places to run cables, they also are conducive to the spreading of fires within buildings, as they are primarily intended to support air flow. Therefore, the National Electrical Code (NEC) specifies that the insulation on plenum cables must be fire retardant, low-smoke and low-toxicity.Cat5e Outdoor Cable Some cables are "UV rated" meaning they can be exposed to outdoor UV radiation without significant destruction. The materials used for the mantle are usually PVC. Any cable which contains air spaces can breathe in moisture, especially if the cable runs between indoor and outdoor spaces. Warm moist air can cause condensation inside the colder parts of the cable outdoors. It may be necessary to take precautions such as sealing the ends of the cables. Some cables are suitable for "direct burial", but this usually requires that the cable is gel filled in order to hinder moisture migration into the cable.Cat5e Shielded Cables (FTP/STP) are useful for environments where proximity to power cables, RF equipment, or high power equipment may introduce crosstalk, and can also be used where interference with radio receivers or where eavesdropping likelihood should be minimised.