A data warehouse is a database optimized to analyze relational data coming from transactional systems and line of business applications. A data lake is different, because it stores non-relational data from mobile apps, IoT devices, and social media. Data is cleaned, enriched, and transformed so it can act as the single source of truth that users can trust. Different types of analytics on your data like big data analytics, full text search, real-time analytics, and machine learning can be used to uncover insights.”]
Source: https://aws.amazon.com/big-data/datalakes-and-analytics/what-is-a-data-lake/