Inequality and discrimination are the two different concepts. But they are related closely to each other. Inequality may be the difference between caste, creed, culture, language, religion, economic status, educational background etc. Everyone differs from the other in society. Discrimination takes place when one acts against an individual or a community on the basis of difference. A Whim or a prejudice works behind it. If one tries to exploit the other individual who is down in status.
In any way, it is called discrimination. That discriminated individual or community is devoid of the common opportunity or facility provided by the society. It is not at all healthy for a good society.