The two major categories of sexual harassment are quid pro quo sexual harassment and hostile environment sexual harassment. Both can occur in workplaces and other places.
“Quid pro quo” is Latin for “this for that.” A quid pro quo involves an exchange of one thing for another. In this type of sexual harassment, someone with power demands sex from someone with less power. They promise rewards for the sex (or punishment for withholding it). For example, then, a manager could promise a subordinate promotions in exchange for sex.
Creation of a hostile environment does not necessarily involve direct actions such as the one described above. Instead, it occurs when the actions of some create an uncomfortable atmosphere based on sex. The classic example of this is men having pornographic pictures on the walls of workplaces. This can make women feel uncomfortable and disrespected.