Apache Spark is an open-source, distributed computing system designed for big data processing. It allows users to process large datasets quickly by utilizing in-memory computing, which speeds up data retrieval and analysis. Spark supports various programming languages, including Python, Java, and Scala, making it accessible to a wide range of developers. One of the key features of Apache Spark is its ability to handle both batch and real-time data processing. It includes libraries for machine learning, graph processing, and SQL queries, enabling users to perform complex data analysis tasks efficiently. This versatility makes Spark a popular choice for organizations dealing with large-scale data.