Semab Tariq begins a new series:
A database cluster is a collection of multiple databases managed by a single PostgreSQL server. It can be referred to as a data/base directory.
A database is a collection of database objects. Whereas a database object is a data structure used to store objects such as tables, views, indexes, extensions, Sequences functions, etc. In simple words, anything that we can create or store within a database is a database object
Read on to learn more about how Postgres lays out database files and tablespaces.