The British Raj, as it was called, was the rule of the British Crown on the Indian subcontinent, that included India and the present-day Bangladesh, Burma and Pakistan.
The way they entered India, as a private trading company, was manipulative and mean and then their extension of control over our resources, people and systems has been marked in bold in the echelons of the World history as one of distrust, greed, brutal and imperialistic.
For achieving their colonial objectives, they not only made autocratic policies, depriving their subjects of any economic, social and political benefits but also forcefully suppressed any revolt for attaining our rightful freedom from their unsolicited rule. Their direct rule lasting for around ninety years resulted in the bloodshed of millions of brave heart Indians.
It may not be important for the British students to know about their country's colonial rule. But we as Indians should know what they did and how we coped and overcame their tyrannical power.
Check out our Whys and Hows on 'Colonial Policies' and 'Administration and Legislation under the British Rule'.