Racism is the oppression of people based on their race, ethnicity, nationality, national origin or colour. It usually involves the combination of racial prejudice and systemic power.
The law recognises many groups such as Romany Gypsies, Irish Travellers, Jewish people, and Sikhs as racial groups (Equality Act 2010).
As with other types of discrimination, racism can also occur due to a perceived trait. If someone assumes you are of a particular ethnicity and treats you less favourably because of it, it is still racist even if you do not hold that ethnicity.
Historical events such as the slave trade, the holocaust, and other genocides have made certain ethnicities more exposed to racism than others.