Internet, Browsers & E-mail
🔒 Log in to trackInternet, WWW, URL and DNS
🔒 Log in to trackThe Internet is a worldwide network of networks. It grew out of ARPANET (1969). The World Wide Web is one service on the Internet: linked web pages, invented by Tim Berners-Lee in 1989 at CERN. A URL is the address of a page. DNS turns a name like ssc.gov.in into a numeric IP address.
Internet and the Web
The Internet is a worldwide network of networks. Millions of computers and phones connect through it and swap data.
- It grew out of ARPANET, a 1969 project of the US Department of Defense.
- The first two ARPANET nodes were at UCLA and Stanford.
- TCP/IP became its standard protocol suite on 1 January 1983.
The World Wide Web (WWW) is a service that runs on the Internet. It is a set of linked pages that you read in a browser. Tim Berners-Lee invented it in 1989 at CERN. E-mail, FTP, VoIP and streaming are other services on the same Internet.
Tip: Internet is the road system. The Web is one kind of traffic on it. The Internet is older (1969); the Web came later (1989).
Parts of a URL
A URL (Uniform Resource Locator) is the address of one page or file. Read it from left to right.
| Part | Example | Meaning |
|---|---|---|
| Protocol | HTTPS | The rules used for the talk. HTTPS is the secure, encrypted version. |
| Subdomain | www | The host prefix. |
| Domain | ssc.gov.in | The name of the server. |
| Top-level domain (TLD) | .in | The ending. It shows the type or country. |
| Port | 443 | The door number on the server. |
| Path | /exams/ | The folder on the server. |
| File | index.html | The exact page. |
Common domain endings
| Ending | Meaning |
|---|---|
| .com | commercial |
| .org | organisation |
| .edu | education |
| .gov | government |
| .in | India |
DNS, DHCP and ISP
Three helpers make a connection work. Each has one job.
| Helper | Job |
|---|---|
| ISP (Internet Service Provider) | Sells you the connection. Examples: Jio, Airtel, BSNL. |
| DNS (Domain Name System) | Turns a domain name into an IP address. It is the phonebook of the Internet. |
| DHCP | Assigns an IP address to your device. |
| Web server | Stores pages and sends them to browsers. |
An IP address is the number that machines use. IPv4 has four blocks, each from 0 to 255. One example is 142.250.183.14.
Watch: DNS resolves names. DHCP assigns addresses. Exams swap these two on purpose.
What happens when you open a page
- You type a URL in the browser.
- DNS finds the IP address of that domain.
- Your request travels over TCP/IP to the web server.
- The server sends the page back.
- The browser draws the page from its HTML.
Every DNS, URL or ISP question is one stop on this trip.
Small facts that repeat
- Bandwidth is how much data a link can carry. It is measured in bps, Kbps or Mbps.
- Broadband is always-on, high-speed access, such as fibre, DSL, 4G or 5G.
- VoIP (Voice over Internet Protocol) carries phone calls over the Internet.
- A website is a set of related pages under one domain.
- A web portal gathers many services on one page.
Question types you will see
Each type: how to recognise it, the method step by step, and one question to try.
Internet vs WWW and ARPANET history
The words 'The Internet is', 'WWW was invented by', 'the year of ARPANET', or a statement that mixes the Internet with the Web.
Match the Internet with ARPANET, 1969.
Match the WWW with Berners-Lee, 1989, CERN.
Remember the Web is a service on the Internet.
Reject any option that treats the two words as equal.
The two dates and the two names are the only facts asked.
The World Wide Web was invented in 1989 by:
Show solutionHide solution
1989 is the Web, not the Internet.
The Web came from CERN.
Tim Berners-Lee at CERN. The Internet is older, from ARPANET (1969).
URL anatomy
A URL is given and one part is asked: protocol, domain, country code or path. Or the full form of URL.
Split the URL at the slashes.
The start up to :// is the protocol.
The name right after it is the domain.
Everything after the domain is the path.
Each part of a URL has one fixed position.
In https://www.mysite.in/exams/ssc.html, the domain name is:
Show solutionHide solution
https is the protocol.
/exams/ssc.html is the path.
What is left is www.mysite.in.
www.mysite.in
DNS, DHCP and ISP roles
'DNS converts ___ to ___', 'which server assigns IP addresses', 'who provides the Internet connection'.
Find the verb in the question.
Convert or resolve a name means DNS.
Assign an IP address means DHCP.
Provide the connection means ISP.
Each helper has one job, and options swap the jobs.
The server that converts a website name into its IP address is the:
Show solutionHide solution
The job is name to IP address.
That is DNS, not DHCP.
DNS server
Internet full forms and firsts
'Full form of HTTP, HTML, URL, ISP, VoIP' or a pair where one word of the expansion is changed.
Recall the full form word by word.
Compare it with each option.
Reject options with swapped words like 'Hyper Transfer Text'.
Remember HTML is a markup language.
One changed word makes the option wrong.
The full form of HTML is:
Show solutionHide solution
H stands for HyperText.
M and L stand for Markup Language.
HyperText Markup Language. It is a markup language, not a programming language.
Domain endings (TLD)
A domain such as .edu, .gov or .org is given and you must name its type. Or the reverse.
Look at the last part of the domain.
Match it to its meaning.
Check the country code .in for India.
Each TLD has one standard meaning.
A website whose address ends in .gov most likely belongs to:
Show solutionHide solution
The ending is .gov.
.gov means government.
A government body
Order of steps to open a page
'What happens first when you type a URL?' or 'arrange these steps'.
Start with the URL typed in the browser.
Next comes the DNS lookup.
Then the request goes to the web server.
Last, the browser shows the page.
The IP address must be known before a request can be sent.
After you type a URL, the browser first asks which service for the server's IP address?
Show solutionHide solution
Names are turned into IP addresses by DNS.
This happens before the request is sent.
DNS
Shortcuts that save time
The Internet is the hardware network of cables, routers and servers. The WWW is the content service of linked pages on top of it. The Internet is older (1969). The Web is 1989.
Who invented the World Wide Web?
Show solutionHide solution
The Web is the service of linked pages.
It was created in 1989 at CERN.
Tim Berners-Lee
DNS turns names into numbers. It never assigns IPs (that is DHCP) and never sends mail (that is SMTP). Any line that says 'converts domain names into IP addresses' means DNS.
What does DNS do?
Show solutionHide solution
Look for the words name and IP address.
Name to number is the phonebook job.
It resolves domain names into IP addresses.
Mistakes to avoid
Where most students lose marks on this subtopic.
Treating WWW and the Internet as the same thing.
The Internet is the network. The WWW is one service that runs on it.
Saying DNS assigns IP addresses.
DHCP assigns addresses. DNS resolves names to IP addresses.
Dating the Internet to 1989.
1989 is the Web (Berners-Lee). ARPANET was 1969.
Calling HTML a programming language.
HTML is a markup language. It describes the page.
Reading HTTP as the secure protocol.
HTTPS is the secure, encrypted one.
Quick revision
Read this the night before the exam.
Internet = network of networks, from ARPANET (1969). WWW = linked pages, Berners-Lee, 1989, CERN.
TCP/IP became the Internet standard on 1 January 1983.
URL = protocol + subdomain + domain + TLD + port + path + file.
DNS: name to IP. DHCP: gives an IP. ISP: sells the connection.
TLDs: .com commercial, .org organisation, .edu education, .gov government, .in India.
HTTP = HyperText Transfer Protocol. HTML = HyperText Markup Language. VoIP = calls over the Internet.
Practice: 16 questions
Sets of 10, mixed across the question types above. Every answer has a step-by-step explanation.
Topic test · 10 questions
Suggested time 5 min · wrong answers go to your mistake notebook automatically.