This document discusses search engines, including what they are, their importance, how they work, types of search engines, and how to use them effectively. It defines search engines as complex software that searches the internet and provides relevant results to users based on keywords. It explains that search engines work by crawling the web to index pages, then presenting search results when users search. The document also outlines different types of search engines and tips for effective searching.

1. SEARCH ENIGINE
PRESENTED BY MR.TAIMOOR KHAN
PRESENTED TO DR.SHAH KHUSRU

2. Contents
1. WHAT ARE SEARCH ENGINES
2. IMPORTANCE OF SEARCH ENGINES
3. HOW SEARCH ENGINE WORKS
4. TYPES OF SEARCH ENGINES
5. HOW TO USE SEARCH ENGINES EFFECTIVELY

3. 1. What are Search Engine
Search engine are complex computer software designed to search information on the
internet and provides the best results to users.
It uses the keywords to search for information's that relate to these key words and
then puts the result in order of relevance to the topic that was searched for.
The search results are generally presented in a line of results, often referred to
as search engine results pages (SERPs) The information may be a mix of links to web
pages, images, videos, articles, research papers, and other types of files

4. 2. Importance of Search Engine
 Search engines are important because with over 8 billion web pages available, it
would be impossible to search for the information that is specifically needed. This
is why search engines are used to filter the information that is on the internet and
transform it into results that each individual can easily access and use within the
matter of seconds
 For example: Searching for MS admission spring 2021 in Pakistan
 If we search in search engine will give list of universities in Pakistan where
admission in started other irrelevant pages will not be displayed so it will be easy
to find the information about MS admission and also saves the time

5. 3. How Search Engine Work
 How Search Engine provides information to user?
 There are Three basic steps to how search engine works
 Crawling: Find out the information's.
 Indexing: Information‘s is analysed and stored in database.
 Search Results: User query is fetched and displayed.
Crawling Indexing
Search
Results

6. Crawling
 Search Engine have number of computer programs responsible for finding
information about the related queries that is publicly available on internet these
programs are called spider,bots or crawlers
 These programs scan the web and create the list of websites
 Then they visit each page of the websites and by reading the HTML code and try
to understand
 The structure of the page.
 Meaning and type of the content.
 When it was created and updated.

7. Indexing
 The contents is then organized and stored in the database
 Indexing decide which page to show and in which order.
 This can be done by search engine Algorithms
 Algorithm working process:
 Analyse user query
The First step is to understand what kind of information user is looking for.
To do that they analyse user queries by breaking down in number of keywords
For example: searching cake baking recipes

8. Continue
 Cake baking recipes will be classified into three keywords cake+baking+recipies
 Pages contain Information about these keywords will be fetched fro the database
 Finding matching pages
 In this step Search engine will look into their index a page that matches best with
the keywords
 Some important factors in matching
 Relevancy of contents and titled with user query

9. Continue
 Popularity of web page
 Date of publications
 For example cake baking recipes
 In first step the query is classified into three keywords cake+bake+recipies
 There will be a lot of contents about these keywords like cake ordering or another
recipes but in this step only those information will be fetched which titled is
matched with the searched query

10. 3.Retrievel/Search Results
 After indexing that information is then displayed to user
 A typical search result page includes 10 organic results
 These results are enriched with other elements like:
 Direct Answers
 Stories and tweet for new related queries
 Images and vedios
 Related Search

11. Continue

12. 4. Types of Search Engine
 Crawler Based Search Engines
 These types of search engines use a "spider" or a "crawler" to search the Internet.
The crawler digs through individual web pages, pulls out keywords and then adds
the pages to the search engine's database. Crawler-based search engines are
good when you have a specific search topic.
 Google and Yahoo are examples of crawler search engines.

13. Types of Search Engine
 Directories
 Directories depend on human editors to create their listings or the database.
Yahoo Directory, Open Directory and Look Smart are few examples.
 Human-powered directories are good when you are interested in a general topic
of search.

14. Types of Search Engine
 Hybrid Search Engine
 Hybrid search engines are search engines that use both crawler based searches and
directory searches to obtain their results .
 Example:- Yahoo.com- Google.com
 Meta Search engine
 These transmit user-supplied keywords simultaneously to several individual search
engines to actually carry out the search. Search results returned from all the search
engines can be integrated, duplicates can be eliminated and additional features such
as clustering by subjects within the search results can be implemented by meta-search
engines.
Example: Dogpile, Met crawler

15. 5. HOW TO USE SEARCH ENIGNES?
 “+” before a word in a search will locate for documents which definitely contain
the word.+
 For example +BLACK+BLUE The search results will contain documents which
contain the word black and the word blue.
 “-” before a word will exclude that word from search.
 For example BLACK-BLUE: Those documents will be returned which contain the
word black but not the word blue.

16. Continue
 Placing words between quotation marks will search for phrase between the
quotes.“ ”
 For example . “BLACK BLUE”: Those documents will be returned which include the
phrase black blue. (placed together).
 Using “or” between search phrase will search each term separately.
BLACK OR BLUE: Those documents will be returned which contain the term black or
the term blue.