Search Engines
Introduction
Search Engine refers to a massive database of internet sources for example web pages, newsgroups, applications, images etc. It aids to locate info on Planet Wide Web. Get extra information about Search engine Meekd
User can look for any info by passing query in type of search phrases or phrase. It then searches for relevant info in its database and return to the user.
Search Engine Elements
Commonly there are actually 3 basic elements of a search engine as listed under:
Web Crawler
Database
Search Interfaces
Web crawler
It is actually also known as spider or bots. It can be a software element that traverses the web to gather information.
Database
Each of the data around the web is stored in database. It consists of enormous web resources.
Search Interfaces
This component is an interface amongst user along with the database. It helps the user to search via the database.
Search Engine Working
Web crawler, database and also the search interface will be the significant component of a search engine that in fact tends to make search engine to operate. Search engines make use of Boolean expression AND, OR, Not to restrict and widen the results of a search. Following would be the actions that are performed by the search engine:
The search engine appears for the keyword within the index for predefined database as opposed to going directly towards the web to look for the keyword.
It then uses software to search for the info within the database. This software component is called web crawler.
As soon as web crawler finds the pages, the search engine then shows the relevant web pages as a result. These retrieved web pages usually contain title of web page, size of text portion, initially several sentences and so on.
These search criteria may perhaps differ from one search engine for the other. The retrieved information is ranked based on a variety of factors for instance frequency of key phrases, relevancy of facts, hyperlinks and so forth.
User can click on any from the search results to open it.
Architecture
The search engine architecture comprises of your 3 standard layers listed under:
Content collection and refinement.
Search core
User and application interfaces
Search Engine Processing
Indexing Course of action
Indexing procedure comprises of the following three tasks:
Text acquisition
Text transformation
Index creation
TEXT ACQUISITION
It identifies and shops documents for indexing.
TEXT TRANSFORMATION
It transforms document into index terms or features.
INDEX CREATION
It requires index terms created by text transformations and make information structures to suport quickly looking.
Query Process
Query method comprises on the following 3 tasks:
User interaction
Ranking
Evaluation
USER INTERACTION
It supporst creation and refinement of user query and displays the results.
RANKING
It uses query and indexes to create ranked list of documents.
EVALUATION
It monitors and measures the effectiveness and efficiency. It really is performed offline.