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KwickAcademy Networks and the Internet · 7 min · free

Search Engines and Finding Information Online

7 min4 KwickClipsFull text belowFree
Next lesson →Kajal Ma'am (MCA), teaching since 2004Remembered in this browser

Learn the three stages of a search engine, how to write a good query with operators, how to judge if a source is reliable, and how to search safely. A search engine crawls pages, stores their words in an index, and then ranks the results.

Follows the syllabus of: CBSE Class 10 Computer Applications (165), NIOS Senior Secondary Data Entry Operations (336)

On screen in this lesson

What is a search engine?

A website that finds web pages for you
Examples: Google, Bing, DuckDuckGo
It is not the same as a web browser
It shows a list of results for a query

Three key terms

TermMeaningLike
Crawlingvisiting pagesa surveyor
Indexingstoring wordsa book index
Rankingordering resultsa merit list

Reading a results page

Ads or Sponsored results are paid
Each result has a title, link and snippet
An AI summary may appear on top
Always check which website a result is from

Writing a good query

AddWeak queryBetter query
Board, classmy exam whenCBSE 10 date sheet
Budgetphone goodphone under 15000
Exact topicscience helpphotosynthesis MCQ

Search operators

OperatorExampleDoes
" " quotes"Tata Nano"exact phrase
- minusjaguar -carleaves a word out
site:site:cbse.gov.inone website
filetype:filetype:pdfone file type

Pause and predict

Query: python -snake
Which pages come first?
Pages on the Python language, not the snake

Quick answers

Does a search engine search the live web when you type?

No. It looks in its own index of pages it has already crawled.

What does the query python -snake return?

Mostly pages about the Python programming language, because minus removes the snake pages.

KwickClips from this lesson

Short clips, one idea each. Good for revision the night before.

The full lesson, in text

Hello students, welcome to Kwickprep. You search for your board exam date, and the first result shows a date. Is the top result always correct? Not always. Today we will learn how a search engine works and how to write a good query. We will also learn to judge if a source is reliable, and to search safely.

First, a simple meaning. A search engine is a website that helps you find information on the World Wide Web. Common search engines are Google, Bing and DuckDuckGo. A search engine is not a browser. A browser like Chrome is the app that opens websites, and the search engine is one of those websites. You type a query, which means the words you search for, and it shows a list of matching pages.

A search engine works in three big stages, called crawling, indexing and ranking. First, programs called crawlers, or spiders, keep visiting web pages and following their links. The words and details of each page are stored in a huge list called an index. Later, you type a query. The search engine looks in its index, not the live web, and finds pages that match. Then it ranks them, putting the most useful and trusted pages on top. Finally it shows you the results page, often in less than a second.

Let us fix these three terms with simple comparisons. Crawling means visiting pages to discover them, like a surveyor going house to house. Indexing means storing the words of pages in an organised list, like the index at the back of your textbook. Ranking means arranging results in order, like a merit list where the best comes first.

Now look carefully at a results page. Results marked Ad or Sponsored are paid for, so they are not always the best answer. Each normal result shows a title, the web address and a short snippet of text. Many search engines now show an AI summary on top, which can be useful but can also make mistakes. So always check which website the information really comes from.

A good query uses a few clear keywords, which are the most important words of your question. My exam when is too vague, so add the board, class and the words date sheet. Phone good tells nothing, so add your budget, like under fifteen thousand. Science help is too wide, so name the exact topic and what you need, like photosynthesis MCQ.

Search operators are special symbols that make a query more exact. Quotes around words find that exact phrase, in that same order. A minus sign before a word leaves it out, so jaguar minus car gives the animal, not the car. Site colon searches inside one website only, such as the official CBSE site. Filetype colon finds only one kind of file, such as PDF notes.

Pause and predict. You type python, then a space, then minus snake. Which pages will you mostly get? You will get pages about the Python programming language, because the minus sign removes pages about the snake.

A reliable source is one you can trust to be correct. Ask five questions before you believe a page. First, who is the author, and do they know the subject? Second, is it an official website, like a dot gov dot in site for the government or dot ac dot in for a college? Third, check the date, because old pages may have outdated rules. Fourth, ask whether the page wants to inform you, or to sell something or scare you. Fifth, cross-check the fact with at least two other trusted sources.

Let us sort some sources by trust. A notice on the official board website is highly reliable. The NCERT textbook website is also official and reliable. A personal blog may be helpful, but check its facts twice. A forwarded WhatsApp message is not a source at all until you confirm it elsewhere. A page full of pop-up ads and shouting headlines needs extra care.

Two special warnings for today's internet. Fake news means false stories made to look like real news, often to spread fear or earn clicks. Before sharing, check the date and find the original source. AI chat tools and AI summaries can sound very confident and still give wrong facts. So open the linked source and confirm the fact before you use it in a project.

Now let us learn to search safely. Fake websites copy real ones, so read the web address before clicking a result. Look for HTTPS at the start, and check the spelling, because a fake site may use cbse dash result dot com. Download apps and files only from official websites or app stores. Never type your OTP, passwords or bank details on a page you reached from a random result. Turn on SafeSearch, a setting that hides adult and violent content.

Searching also leaves a trail, so protect your privacy. Search engines may save your searches in your account history. On a shared computer, use a private or incognito window, which does not keep history on that device. Always log out on a school or cyber cafe computer. And when you use text or images you found, respect copyright and give credit to the source.

Let us revise what we learned today. A search engine crawls pages, stores them in an index and ranks the results. Good queries use clear keywords and operators like quotes, minus and site colon. Judge a source by its author, website, date and purpose, and cross-check it. Ads and AI answers are not automatically correct. And search safely, by checking addresses and never sharing your OTP or passwords.

Courses that teach this

CourseUnit
CBSE Class 10 Computer Applications (165)Networking
NIOS Senior Secondary Data Entry Operations (336)Lesson 10: Internet

Voice-over in this lesson is AI-generated. The script is written and checked by Kajal Ma'am. Boards can revise a syllabus mid-year, so confirm anything you plan around against the official board circular. Keep your passwords, OTPs and ID numbers to yourself — we never ask for them. To reach Kajal Ma'am, use the WhatsApp button; sharing your number there is how we call you back.

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