What is Category 5, 5e & 6 (CAT5, CAT5e CAT6)?

This is a performance designation for twisted pair cable and connectors specified up to 550 MHz and data rates of 100 Mbps. Cat 5 performs at up to 100MHz while Cat 5e performance reaches up to 350MHz. Newer Cables called Cat 6 are rated at 550Mhz. Both Category 5 and Category 5e consist of unshielded twisted pair with 100 ohm impedance and electrical characteristics supporting transmissions up to 550 MHz. Cat 5e (350MHz) and Cat 6 (550MHz) improve on the original Cat 5 (100MHz) design by adding more shielding through extra twists to the wire. Cat 6 places a divider inside the inner core to separate the wire pairs even more than Cat 5e. The differences between Category 5 and Category 5e are in transmission performance. Category 5e components are most suitable for a higher-speed Ethernet. Gigabit Ethernet applications reaching 1000 Mbps should use Category 6 cabling for best results.
 

What the difference between Ethernet, Straight-through, and Patch Cables?

Absolutely nothing. These three terms are synonymous when talking cable.
 

Category 5 vs. Category 5 Enhanced (5E)

Cat 5 is an old standard, most cable manufactures don't even make it anymore. Cat 5E is what should be used in today's higher speed networks. Cat 5E is fully backwards compatible with all Cat 5 products and networks. Cat 5E builds on the old Cat 5 design but adds more twists to the wire pairs to allow for higher transmission speeds up to 3 1/2 times that of the old Cat 5 cable...from 100MHz to 350MHz!!

Although Cat 5 may work there is no reason NOT to spend a few more dollars on a better, faster cable...Cat 5E

Copper RJ45 vs. Gold plated RJ-45 (50µ & 3µ)

Most people don't realize there are differences in the end connectors called RJ-45 8p8c plugs. They may all appear to look a like but the difference lies in which materials make up the contacts. Some are made with Copper while others are plated with Gold. As you may have guessed Gold is the best contact material used... but here is the catch! There are different concentrations of Gold plugs. Some are 3µ (3 microinches) of Gold while the best are 50µ (50 microinches) of Gold. 50µ is almost 20 Times as thick as 3µ plugs!

Never buy a cable with only 3µ of Gold (wears off quickly) or worse a Copper connector. Good cables (Cat 5E & Cat 6) will have 50µ Gold plating. Warning!! If the advertisement doesn't state 50µ Gold Plating then THEY ARE NOT!! If it only states "Gold plated" then chances are it's only 3µ Gold which will wear off after only a few times plugging them in and out of the socket.
 

What is a Crossover Cable?

A crossover cable is a segment of Category 5 (5e) cable that crosses over pins 1&2 and pins 3&6. This cable is normally used to connect two PCs (Peer to Peer) without the use of a hub or router. One cable hooks directly into the back of both computers using a standard Ethernet Network Interface (NIC) card with RJ45 ports.

What is the difference between 10BASE-T, 100BASE-T and 1000BASE-T?

10BASE-T is the IEEE standard that defines the requirement for sending information at 10 Mbps on unshielded twisted-pair cabling, and defines various aspects of running Ethernet on this cabling. 100BASE-T is the IEEE standard that defines the requirement for sending information at 100 Mbps on unshielded twisted-pair cabling, and defines various aspects of running baseband Ethernet on this cabling. 1000BASE-T is the IEEE standard that defines the requirement for sending information at 1000 Mbps on unshielded twisted pair cabling, and defines various aspects of running baseband Ethernet on this cabling.