A data lake is a centralized storage system that holds vast amounts of raw data in its native format until it is needed. Unlike traditional databases, which store structured data, data lakes can accommodate unstructured and semi-structured data, making them versatile for various data types, such as text, images, and videos. This flexibility allows organizations to store data without the need for immediate processing or organization. Data lakes are often built on cloud platforms, enabling easy scalability and access. They support advanced analytics and machine learning, allowing businesses to extract valuable insights from their data. Popular technologies used to create data lakes include Apache Hadoop and Amazon S3.