This case was a case (ruled on in 1998) about gay rights under the Canadian Charter of Rights and Freedoms. In this case, the Supreme Court of Canada ruled that homosexuals had the right to be protected from discrimination on the basis of their sexual orientation.
Delwin Vriend was a teacher at a private religious college in Alberta. The college asked him to resign when he informed administration that he was gay. This request was made based on the idea that homosexuality was contrary to the religious mandate of the college. Vriend refused and was fired on the basis of his sexual orientation.
Alberta's law protecting individual rights did not state that discrimination based on sexual orientation was illegal. However, the Supreme Court held that Alberta's law was incompatible with the Canadian Charter since the Charter (the court said) should be read to protect homosexuals against discrimination.