Why is containerization needed? Why not just deploy?

Containerization is needed for standardization and isolation of application runtime environments. Unlike simple deployment, containers allow:

• Ensuring the same environment at all stages — from development to production, which reduces "it works on my machine" problems.
• Isolating dependencies and configurations so that different applications do not conflict with each other.
• Simplifying scaling and managing applications with orchestrators (e.g., Kubernetes).
• Fast deployment and updates due to the lightweight nature of containers.

Example: instead of installing all libraries and settings on a server, you package the application with the necessary dependencies into a container, which runs the same everywhere.