Azure Data Lake Analytics provides a big data analytics service for processing large amounts of data stored in Azure Data Lake Store. It allows users to run analytics jobs using U-SQL, a language that unifies SQL with C# for querying structured, semi-structured and unstructured data. Jobs are compiled, scheduled and run in parallel across multiple Azure Data Lake Analytics Units (ADLAUs). The key components include storage, a job queue, parallelization, and a U-SQL runtime. Partitioning input data improves performance by enabling partition elimination and parallel aggregation of query results.