What changes after this module
Understand how data moves between systems, where trust boundaries sit, and why transport decisions shape exposure.
Outcome promise
- Explain a simple request flow across devices, networks, and services.
- Identify one trust boundary and one exposure point in a networked journey.
Core model
Use the diagram and terms below as the minimum model you should be able to explain after this module. If you cannot explain the model in plain language, pause here before you move on.
Key terms
- Packet
- A unit of network communication carrying data between endpoints.
- Trust boundary
- A point where assumptions about identity, control, or safety change.
Check yourself
Answer the prompt before you reveal the check. If you cannot answer it in your own words, revisit the model and the terms once more.
Quick check
What changes when a request crosses a trust boundary?
Reveal the answer check
You need fresh checks on identity, input, policy, and protection because the old assumptions no longer hold safely.
Reflection and evidence
Keep the evidence small. One honest reflection and one small artefact is enough to show that the learning changed how you describe, check, or design something.
Reflection prompt
Pick one service you use. Where does the first meaningful trust boundary appear in its journey?
Artefact
A simple request-flow sketch with one trust boundary and one control point.
Optional deeper practice
Use the workspace to trace a request across a boundary and note what you would validate at each step.
Move through the course
Keep the flow predictable. Stay with the stage sequence unless you have a clear reason to jump around.