In ancient times (See Odysseus), the boat had to use rear wind (propulsion) and therefore wait the right wind directions to start its cruise
Modern sailing boats are able to go against the wind from an average of 40 degrees, to 25 degrees for modern (America's cup type) racing boats.
Sailboats typically have one, two, or three hulls. Vessels with one hull are known as monohulls, those with two or more are known as multihulls. Multihulls can be further subdivided into catamarans (two hulls), and trimarans (three hulls).
Sailing can be further divided into two areas: