What are the difference between proactive and reactive people?

Proactive people try and eliminate problems before they even appear. They are usually looking ahead at future events, problems, activities, etc. The prefix "pro" means before, so these people are prepared before things happen.

Reactive people respond to problems after they have happened. They usually aren't looking ahead, and don't take a lot of initiative in life. These people "react" to issues.

The difference between proactive and reactive people are how they preform their beliefs or respond to the thing, its kinda like bystander and someone who gets involved.