To explain what critical thinking is, we should first define what thinking means. Thinking refers to an individual's intellectual or mental activity which involves an individual's consciousness. Thinking allows an individual to make sense of the world in a variety of ways and at the same time interpret it in ways that are meaningful to them according to their attachments, needs, plans, objectives, desires, commitments and ends. As a human being, we all want to satisfy our ego, that is why we have our own selfish interests and no one always acts rationally, purely and objectively. From this concept, we develop the way of critically thinking in order to get what we want, this is called critical thinking. We define critical thinking as a self-directed, self-monitored, self-corrected and self-disciplined way of thinking that is why it could sometimes be biased, down-right prejudiced, distorted, uninformed or partial. Critical thinking is the way of skillfully applying, analyzing, conceptualizing and synthesizing and/or evaluating information which has been gathered from experience, observation, reflection, communication or reasoning as an individual's own guide to his/her action and belief. Critical thinking is varying according to its underlying motivation because it is a self-guided discipline which tries to reason at the highest level of quality that it can, while at the same time being fair minded.

Critical thinking is the way of questioning assumptions and deciding whether that assumption is true, false, or partially true. It is also being described as "reasonable reflective thinking focused on deciding what to believe or do" and "thinking about thinking". Critical thinking examines assumptions, clarifies goals, evaluates evidences, discerns hidden values, assesses conclusions, and accomplishes actions. Critical thinking involves a combination of some complex skills which includes: self-awareness by weighing the influences of our bias and motives, rationality by relying on our reason than our emotions, open-mindedness by considering a variety of perspectives, honesty by recognizing our emotional impulses, judgments by recognizing the weight and extent of evidence, and discipline by resisting irrational appeals and manipulation.