Web Technology Fundamentals and Internet Concepts
What the exam tests
Internet versus WWW, the client–server model, HTTP/HTTPS, URL anatomy, DNS, IP addressing, and static versus dynamic pages.
Core rules
- The Internet is the global network of networks; the WWW is a service running on it using HTTP/HTTPS.
- A client browser sends a request; a server returns a response with a status code and resource.
- HTTP default port is 80; HTTPS default port is 443 and uses TLS.
- URL form: scheme://host:port/path?query#fragment.
- DNS maps domain names to IP addresses. Common records: A, AAAA, CNAME, MX and TXT.
- Static pages are served as stored; dynamic pages are generated by server-side code or client-side scripts.
Worked example
https://www.example.com:443/products/item.html?id=7#reviews Scheme = https; host = www.example.com; port = 443; path = /products/item.html; query = id=7; fragment = reviews. The fragment is handled by the browser and is not normally sent to the server. Because the scheme is HTTPS, traffic is encrypted with TLS.
Traps
Do not say the WWW and Internet are identical. Do not put the query before the path. Do not claim HTTPS encrypts the domain name in DNS lookups. Do not confuse a domain name with hosting. Status 404 means not found, not server down.