Prohibited or unlawful conduct under the Equality Act is defined in a number of ways that seek to protect individuals who are disadvantaged by a number of types of behaviour.
Less favourable treatment
The first type of conduct is where the individual is treated less favourably than a person who does not share the same protected characteristic. This is called 'direct' discrimination.
Direct discrimination requires that the less favourable treatment is 'because of' the protected characteristic rather than some other unrelated cause. Generally this requires a comparison to be made between the way you have been treated and the way another person has been or would be treated.
Discrimination can also arise where a rule or practice operated by the employer causes more disadvantage to a person in a group which shares a protected characteristic. This is called 'indirect' discrimination.
If a person is subjected to offensive or humiliating behaviour for reasons relating to a protected characteistic then they may be being suffering unlawful harassment.
Victimisation has a particular definition in the Equality Act and occurs when a person is subjected to detrimental treatment because they have done a 'protected act'.
Protected acts are generally asserting or preparing to assert rights under the Equality Act or helping others to do so.
Failing to make reasonable adjustments
Where a person is disabled and put at a disadvantage in the workplace an employer has a duty to make reasonable adjustments to the work or workplace to enable the employee to overcome that disadvantage.
Discrimination arising from disability
Where a person is disabled and they are treated 'unfavourably' because of something that arises in consequence of their disability they may be suffering discrimination.