Critical thinking is necessary to evaluate information effectively. It involves distinguishing facts from opinions, evaluating supporting evidence, and detecting bias. Facts can be proven true or false, while opinions are subjective judgments that can be supported by evidence from reliable sources. Not all information is accurate, as some writers have political or commercial biases and use emotionally charged language to influence readers regardless of the facts. Developing critical thinking skills allows one to analyze information rigorously and discern what is most important.