What is the C4 Model and what levels does it consist of?

The C4 Model is a method of visualizing software architecture, consisting of four levels (from general to specific):

1. Context — shows the system in its environment, its users, and external systems it interacts with.

2. Container — breaks down the system into high-level parts (applications, services, databases), showing how they interact.

3. Component — details the containers, showing internal components and their relationships.

4. Code — the most detailed level, showing the code structure, classes, or modules within components.

This approach helps to systematically reveal the architecture, starting from an overall overview and ending with implementation details.