A data source is any location or system where data is stored and can be accessed for analysis or processing. This can include databases, spreadsheets, online repositories, or even physical records. Data sources provide the raw information needed for various applications, such as business intelligence, research, and machine learning. Data sources can be categorized into two main types: primary and secondary. Primary data sources are original data collected firsthand, like surveys or experiments, while secondary data sources compile existing information, such as reports or articles. Understanding the type of data source is crucial for ensuring the accuracy and relevance of the information used.