Internet, Networking and Web Basics
Internet, Networking and Web Basics tests how devices connect, how addresses and URLs work, and how web pages are requested. Expect definitions, device roles and safe browsing distinctions.
Core rules
- A network connects devices to share resources. LAN is local (school lab); WAN spans large areas (the Internet is the largest WAN). Topologies include star, bus and ring; star is common because one cable failure does not stop the whole network.
- A client requests services; a server provides them. A router forwards traffic between networks; a switch connects devices within a LAN; a modem converts signals for the ISP link.
- Every device has a MAC address (hardware) and an IP address (logical). DNS translates a domain name into an IP address. HTTP/HTTPS transfer web pages; HTTPS encrypts traffic. FTP transfers files; SMTP sends email.
- A URL identifies a resource: scheme, host/domain, path, query and fragment. A web page is one document; a website is a collection of pages under a domain. A browser renders pages; a search engine indexes them.
Worked example
Parse https://www.example.com/notes/page.html?topic=ip#section2. Reasoning: https is the scheme (secure HTTP); www.example.com is the host/domain; /notes/page.html is the path to the page; topic=ip is the query string; #section2 is the fragment pointing to a page section. The domain is example.com; www is a subdomain. DNS would resolve example.com to an IP address before the browser connects.
Traps
- Saying a search engine is a browser; Google Search and Chrome are different.
- Treating HTTP and HTTPS as equally safe; HTTPS adds encryption.
- Confusing an IP address with a domain name.
- Calling the whole URL the domain name.
- Assuming a LAN must connect to the Internet; it can work locally.