MyDB

1️⃣ What is a User Database?

A user database is a database created by a user for real work.

Examples:

• MyDB (in my case)

• school_db

• blog_db

User databases store:

• Application data

• Tables

• Business logic

• User schemas

2️⃣ Default vs User Databases

Feature	Default Database	User Database
Created by	PostgreSQL	User
Purpose	System / admin	Application data
Safe to store data?	❌ No	✅ Yes
Deleted normally?	❌ No	✅ Yes
Used by apps	❌ Never	✅ Always

Databases (2)
|__ MyDB  ← user database
└── postgres   ← default database

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3️⃣ Real-World Analogy

Think of PostgreSQL like an office building:

PostgreSQL	Real world
Server	Building
Default database	Reception
User database	Office room
Tables	Cabinets
Rows	Files

You work in office rooms, not at reception.

Note

Summary

Databases are logical containers that organize and isolate data inside a PostgreSQL server.