The federal employment discrimination laws cover only harassment that is related to those classes protected by the laws: gender, race, ethnicity, etc. So, general harassment that is not based on one of these protected classes is not covered by the employment discrimination laws. The most common form of harassment that is covered by discrimination laws is sexual harassment, but the following applies to harassment based on the other protected classes. In order for harassment to fall under the federal law, it must be sufficiently severe or pervasive. This means that there must be at least a few fairly severe incidents or numerous incidents that, by themselves, are not severe. For example, a few instances of physical groping would probably suffice on the one hand, and sexual remarks made on a regular basis for weeks or more should suffice.
It is important to note that the harassment must be discriminatory in nature. For example, if a supervisor puts his arm around female employees, but he also does this in the same manner to male employees, this is probably not sexual harassment because women are not treated differently than men. Also, sexual harassment is not limited to conduct that is sexual. It also includes chauvinism. So, if a supervisor frequently makes derogatory remarks about women as a gender, this can be sexual harassment.