Diffrent strings?

[king_xanadu]

I have round wound strings
and i know what flatwound strings are
but can some one explain to what half wound and hex wound are
and if there are other types

[Parabolic Box]

Half wound are roundwounds that have taken a shave to get a smoother surface. They're also called groundwound.

There's no such thing as hex-wound. Hex core, on the other hand, refers to the profile of the core wire, which is, unremarkably, hex-shaped. Typically provides a stiffer string, though other benefits are subjective.