Cat5 cable is the original Ethernet cable, and includes four twisted pairs in a single jacket. The twisted pair design helps reduce interference from external sources and other pairs (also known as crosstalk). Its performance specifications were designed for use with up to 100Mbit/s networks in fact, the most common usage for Cat5 cable is 100BASE-TX Ethernet.
In 2001, Cat5e (or enhanced Cat5) was designed, with stricter specifications for performance and speed. The biggest difference between Cat5 and Cat5e is that Cat5e can be used with Gigabit networks, networks like 1000BASE-T that boast transfer speeds of up to 1000Mbit/s. Cat5e also has slightly modified wiring for even greater protection from far end crosstalk.
In general, Cat5 has been almost completely replaced by Cat5e. While you can still find Cat5 cable out there, you can often find Cat5e at almost the exact same price. You may not notice a difference in performance for a home network, but virtually all business settings will benefit from exclusively using Cat5e.
UTP or STP?
The "TP" in both STP and UTP stands for "Twisted Pair." As mentioned previously, Cat5 cables include 8 total wires, each twisted with another to create four twisted pairs. This balanced pairing is crucial in avoiding crosstalk and establishing a high signal-to-noise ratio even in interference-rich environments.
STP is Shielded Twisted Pair. Each pair in the cable is covered in a metal sheath, which provides protection against EMI (Electromagnetic Interference). The drawbacks to shielding are a heavier cable without the same level of flexibility as UTP (Unshielded Twisted Pair). STP is also a slightly more expensive cable and all of its jacks and terminators are shielded to be effective, which can add up over long distances.
UTP has no additional shielding around its individual twisted pairs, and thus does not require that its terminators and jacks also be shielded. Additionally, it is a light, thin, and flexible cable. This means that it is easy to wire between walls and won't take up the space that you may need for additional wiring.
Conclusion
Unless you have specific needs, UTP Cat5e cable is the best solution for most of your networking needs. Not only is it reliable, fast, and easy to work with, it's also the cheapest LAN cable on the market.
For additional shielding, go ahead and pay the extra for STP but remember that the cable will have less flexibility and needs shielded counterparts when planning your networking.
