It has pretty much been said but I'll put it all together. ALL cat 5 cables are twisted pair. That is a term discribing the construction of the cable itself. It consists of 4 pairs of wire, each pair twisted together.
Straight or crossover discripes how the CONNECTORS are wired. In the crossover cable the receive pin on one end connector is "crossedover" to connect to the Transmit pin on the other end of the cable.
I am sure this is clear as mud.
good luck