Discrimination is defined as the practice of unfairly treating a person differently from other people. It can happen anywhere and anytime like discrimination at work . Discrimination is an unjust treatment on the grounds like race, sex or age. Discrimination against homosexuals or racial discrimination are common examples. How do we fight discrimination?
Act and educate yourself about discrimination is the first thing to do. 
Speak up when you hear offensive jokes. Discriminatory speech and actions should be denounced. You have to learn to speak up to let everyone know that biased actions and speech are never acceptable.  
Explore your own stereotypes. Get involve on community outreach activities. 
You have to unite and dig deeper as to where you fit in. Learning about lives of people with diverse characteristics can be done through reading. It is also a good way to learn how different are your experiences from others. 
You can start to change the way you think about individual differences by being aware of the words you use. The words you use can affect the ways you organize your world and others. The words you use can often be your subconcious way you perpetuate discrimination.