PostgreSQL, also known as Postgres, is a free and open-source relational database management system (RDBMS) emphasizing extensibility and technical standards compliance. It is designed to handle a range of workloads, from single machines to data warehouses or Web services with many concurrent users.
A database is a place where you can store, manipulate and retrieve data. SQL is a programming language used to interact with databases. SQL allows you to manage data in a relational database. Data in a relational databases is stored in columns and rows, think Tables.
Object-relational database management system. Modern. Open Source.
Connecting to a DB Server can be done via a GUI client or via the command line. Utilizing the command line for database management will provide you with an additional level of control over how other technologies connect with your database server.