Information sources are materials or channels that provide data, facts, or insights on various topics. They can be categorized into primary sources, like original research articles or interviews, and secondary sources, such as textbooks or news articles that analyze or summarize primary data. Common information sources include libraries, databases, and the internet. Each source has its strengths and weaknesses, with some offering peer-reviewed content while others may contain unverified information. Understanding the reliability and purpose of each source is essential for effective research and informed decision-making.