Both cables are a sequence of twisted pair high signal integrity cables.  The maximum length of the cables are 100m (328 ft), any length after that will have problems involving loss of data. With both cables having the ablility to host a 100 Mbits(Megabits) or a 1000BASE-T Gigabit ethernet network.

The only difference between Cat5e and Cat6 is in the transmission performance and the extension of bandwidth.  Cat5e provides a bandwidth of 100MHz (megahertz), while Cat6 can provide up to 250MHz.  The improvements provide a higher signal-to-noise ratio giving a higher reliability to current applications and higher data rate for future ones.

Both forms of cables come in standard, solid, shielded, or plenum.  Standard cables are very flexible and generally used to create patch cables.  Solid cables are not as flexible due to the thicker jacket of the cable since it is designed for wall installations.  Shielded cables are used more for a specific location with a high position and a high interference or crosstalk.  You can read about plenum cables in an earlier blog.

Another concern when picking out cable is deciding between FTP, STP, and UTP.  FTP (Foiled Twisted Pair) and STP (Shielded Twisted Pair) are just alike in the function of wiring, the only differences is in the protection covering the wires from electromagnetic fields.  FTP has a two part protection of foil and PE (polyethylene) tape protecting the wires.  STP adds another layer of PE tape on top of the foil for extra protection. You can view these differences by clicking on image.  But most cables come as UTP (Unshielded Twisted Pair), which only has a jacket protecting the wires inside.  UTP is common in cables, because it is less expensive and easier to work with.