Final answer:
The unequal treatment of people from different categories is considered discrimination, which can be legally and socially challenged.
Step-by-step explanation:
When people from different categories are treated unequally, it is considered to be discrimination. This involves the unjust or unequal treatment of individuals or groups based on characteristics such as race, age, or gender identity. Various laws in the United States and international conventions like the ones from the United Nations aim to forbid discrimination on multiple grounds. Discrimination can take many forms, including unfair housing practices, biased hiring systems, and other actions that result in unequal treatment of people. Discrimination can occur based on factors such as race, age, gender identity, religion, or national origin. It is important to promote equality and respect for all individuals, regardless of their differences.