General IT knowledge

About these general IT topics

These are practice topics, not vendor exams. They cover the foundations that every cloud, DevOps and software role takes for granted: networking, operating systems, databases and SQL, and security fundamentals. Cloud certification guides rarely teach this material. They assume it, and a question about subnets, IAM or a managed database is much harder when the idea underneath is shaky.

The questions are vendor-neutral. They are written from the standards and references the subjects are built on, such as the RFCs behind TCP, DNS and IP addressing, NIST definitions for security terms, standard SQL with PostgreSQL as the reference behaviour, and the classic structure of operating systems teaching: virtualisation, concurrency and persistence.

Who they help

• People starting their first cloud certification. Networking and security fundamentals make the networking and security domains of AWS, Azure and Google Cloud exams far easier, because those domains reuse the same ideas under product names.
• Interview candidates. Support, sysadmin, backend, DevOps and junior security interviews lean on exactly these topics, usually as a troubleshooting question rather than a definition.
• Students and career changers who learned these subjects from a course and want to check they can apply them to a real situation.

How to use them

Each topic has a 10-question test. Most questions are short scenarios: a host has an odd address, a query is missing rows, two threads corrupt a counter, a site is trusted only because it shows a padlock. You pick what is happening and why. The wrong options are the misunderstandings people really have, so read the explanation of every option, not only the one you chose. Each question also has its own page with a link to the reference it is based on.

A sensible order is networking first, then security fundamentals, then whichever of operating systems or databases matches the work you do. If you are heading for Kubernetes or Linux work, pair operating systems with the Linux and Docker topics in the interview group. If you are heading for data or ML work, do databases and SQL before the Databricks certs.

Your scores are kept in your browser, so you can come back to a topic after studying and see whether you have improved. More tests will be added over time.