This document provides an overview of NoSQL databases and their concepts. It begins with an introduction from the presenter and an agenda outlining the topics to be covered. The document then discusses the history and evolution of database management systems. It introduces relational database concepts and outlines some of the limitations of relational databases in handling big data. This leads to a discussion of the need for database systems beyond relational databases and a paradigm shift in database management. NoSQL databases are then defined as providing alternatives beyond the relational model. The remainder of the document covers types of NoSQL databases and their usage, as well as the future of relational databases.