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
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.