The term 'harassment' is often used loosely in a work setting to describe unpleasant or bullying behaviour. However, in the context of the Equality Act 2010, it has a specific meaning.
The harassment banned by the Equality Act is any unwanted conduct that has the purpose or effect of violating someone’s dignity, or creating an intimidating, hostile, degrading, humiliating or offensive environment for that person, related to a protected characteristic (e.g. sex, race, disability, etc.).
In serious cases (e.g. where a campaign has been waged against someone over a prolonged period), harassment may also be a criminal offence under the Public Order Act 1986 and the Protection from Harassment Act 1997.
Serious harassment that takes place online can also lead to criminal prosecution, for example under the Malicious Communications Act 1998.