Answer:
If you are a student, you may have heard this phrase because teachers hope you will learn how to do this when you read assigned material for class. "Critical thinking" refers to the ability to think logically about what you have read (or heard), to analyze an author's central thesis and then decide whether or not you agree with it.
While the word "critical" is very often used to say something negative (He was very critical of that play and told people not to see it), in the phrase "critical thinking," it has a more positive meaning. When you are using critical thinking, you are trying, as objectively as possible, to evaluate whether something is accurate; you are thinking for yourself about it instead of just believing what everyone else says.
In the world today, there are many myths and false statements you can find online or in the media. The person who knows how to do critical thinking knows how to seek out accurate information and not be fooled or manipulated by claims that seem true but are not.