Choose an exam and explore concepts through visual explanations, topic maps and revision checks. Open the full chapter notes whenever you need more detail.
THE VISUAL LEARNING STUDIO
See the idea. Understand the connection.
35 visual explanations across 29 chapters, with topic maps throughout the library.
The chapter index will grow as additional notes are prepared. Chapters shown here are a learning collection, not a claim that the entire exam syllabus is complete.
SEE IT. CONNECT IT. EXPLAIN IT.
Understand the chapter visually
Start with the topic map, then open each explanation below. Detailed concept diagrams are being added to this chapter.
Use Recall mode to hide explanations; tap or focus a card to reveal one. Expand any diagram for a larger view.
Study the expanded notes and the credited detailed textbook lessons. The current chapter index covers core topics; it is not a claim of exhaustive coverage of every examination syllabus. Check the official syllabus and primary references.
Networks — lesson overview
Connections and addressing
A computer network connects devices for communication using agreed protocols. Local and wide-area networks differ in scope and architecture.
An IP address identifies an interface within an addressing context, while a domain name provides a human-readable naming layer.
DNS resolves names to associated records; it is not itself the physical network or every service hosted on a domain.
Devices and protocols
A switch commonly forwards frames within a local network; a router forwards packets between networks according to routing information.
TCP and UDP provide different transport behaviours. HTTP is an application-layer protocol used for web communication.
A protocol’s role should not be inferred simply from the device’s consumer label; many devices combine several functions.
Internet and troubleshooting
The internet is a network of networks; the web is one collection of services using it. Email and other services do not reduce to web browsing.
A website can fail because of naming, connectivity, server, certificate or application problems; these are distinct possible causes.
Successful DNS resolution alone does not prove the application is working, and a working connection does not prove trustworthy content.
