Published lesson ยท 30 minutes

Understand cloud computing

Objective: Explain what cloud computing provides, compare IaaS, PaaS and SaaS, and identify which responsibilities remain with the people using a service.

Start with the user need

Cloud services deliver computing resources over a network on demand. A team can provision capacity without owning every physical server, but it still makes choices about data, access, configuration and cost. Compare a local computer room with a cloud service: the cloud provider operates physical facilities, while the customer selects and configures services for their needs. A community group needs a website that can grow during event registration and quiet down afterward.

Make the trade-offs clear

For a small learning exercise, keep names and records fictional. First state the user need, then select the simplest design that meets it. Compare the benefit with a limitation such as connectivity, service dependency, configuration effort or recurring cost.

  • IaaS offers building blocks such as virtual machines, networks and disks; the customer configures much of the software stack.
  • PaaS manages more of the runtime so a team can focus on its application and data.
  • SaaS provides a finished application that people use; configuration, access and data handling still matter.

A cloud design is a set of trade-offs rather than a promise. Record assumptions about expected users, sensitive information, connectivity and the people who will operate the service. Revisit those assumptions when the audience or risk changes.

Practice scenario: A community group needs a website that can grow during event registration and quiet down afterward. Choose a fictional community website and compare a small local-server approach with a managed cloud approach. State one benefit, one trade-off and one responsibility that remains with the site team.

Worked examples

Understand cloud computing: a design walkthrough

Walk through a provider-neutral decision for A community group needs a website that can grow during event registration and quiet down afterward. Explain the trade-offs and checks without provisioning a real service.

Practice tasks

  1. Compare two choices

    Choose a fictional community website and compare a small local-server approach with a managed cloud approach. State one benefit, one trade-off and one responsibility that remains with the site team.

  2. Make a reviewable plan

    Prepare a short, fictional plan for A community group needs a website that can grow during event registration and quiet down afterward. Include the service or design choice, the user benefit, a responsibility or risk and one way to check the result.

  3. Explain a trade-off

    Review your understand cloud computing plan from the viewpoint of a learner and a service operator. Name one strength, one uncertainty and a practical next check.

Select a service model by matching the amount of control and maintenance a team can responsibly handle.

Course overview