What is the difference in your mind, and in your common usage, between a perception, a generalization and a stereotype?

What is the difference in your mind, and in your common usage, between a perception, a generalization and a stereotype? Please give an example of each. Are each or all consistently unethical judgments or are they sometimes or always ethically justified in their use and implementation? Under what conditions?

Approx 150 .   due in 14 hours max from posting just a discussion board post