Critical thinking is an important mental process that involves skills like conceptualizing, applying, analyzing, synthesizing, and evaluating information to reach conclusions. It helps with reasoning effectively, using systems thinking, making judgments and decisions, and solving problems. In 21st century education, critical thinking can be applied by identifying significant questions that clarify different perspectives and lead to better solutions, as well as making complex choices and decisions. Technology should be used to promote higher-order thinking skills like analysis, synthesis, and evaluation rather than just drilling for memory.