There are several different types of discrimination. These include ...
RacialDiscrimination based on someone's country of origin, the colour of their skin or the culture they were brought up in.
HomophobicDiscrimination based on one's sexual orientation, considering them lesser beings because they are gay (homophobia,) lesbian (lesbophobia,) bisexual (biphobia,) or pansexual (panphobia.)
SexistDiscrimination based on one's gender. This is not seen as often in the 21st century, but is still prevalent in some cultures. It tends to mostly affect women when it happens, but is not limited to thus, and can include men.
HobbiesOften, people are discriminated based on the activities they enjoy, for instance, online role-playing games which are stereotypically viewed as "nerdy" or "geeky". This is not limited to the internet, and can include practical hobbies such as playing with trains, or collecting stamps, these are sometimes frowned upon.
An aside:
Discrimination is often thought to be entirely a negative activity however it has its positive aspects and applications. In the extreme case, we all tend to avoid (discriminate against) strangers walking through town with a running chainsaw and parts of dogs slung over their backs. In lesser cases we avoid individuals that may harm us, who we owe money to, and who othewise would reduce our quiet enjoyment of life. Similarly employers avoid hiring individulas that have a history of poor work habits or who are otherwise unsuited for the partiuclat job (for real reasons)
