Haze, AKA Purple Haze (Jimi Hendrix sang about it) is marijuana with purple leaves/hairs in it. It gives you an unbelievable high, affecting your mind moreso than your body. It feels more like an acid trip than a pot high, and many people claim that this weed is laced with PCP, but it is not.
Purple Haze is also used to describe PCP itself, and the high is very similar, but PCP is not smoked. The acid would break down before you could smoke it.