Why do you need volumes?

Volumes are needed to store data independently of the container. A container is a temporary thing: it is easy to recreate, delete, or update. If data is stored inside the container, it disappears along with it. A volume solves this problem.

The main reasons volumes are used:

#1. Data durability

The database, files, settings, and logs do not disappear when the container is rebuilt or removed.

#2. Separation of concerns

The container runs the application, while the volume stores the state. This makes the system cleaner and more convenient.

#3. Safe updates

You can update the image without fear of losing data - the volume connects to the new container.

#4. Convenient work with services like PostgreSQL/MySQL

Databases cannot live without persistent storage, so a volume is a standard tool.

Summary: a volume is needed so that data outlives the container and remains accessible regardless of its lifecycle.