Web Search

Internet search engine (Search Engine) - a program with an interface for users to search for and display information according to the user's query.



The types of search engines:

• Global - designed to search for information on the Internet;


• Local - searches the local network or specific services.

There are the following global search systems:

• Universal - search engines give your users the ability to search the content of any type: text, graphics, audio, video. Simply searching in network resources. The world leader in the midst of universal search engine is Google. Besides him, there are quite familiar Yahoo!, Bing, Yandex, Baidu. In Poland, the Google search engine handles about 98% of the requests. In addition to self-service Google.pl, the company serves customers such sites as Onet.pl, Interia.pl or Gazeta.pl;


• specialized - their job is to find information that meets these requirements. These systems find files on FTP servers, goods in online stores information in Usenet (newsgroups worldwide system);


• 
  ideas - a search engine such seek only the information on the Internet
  that may be of interest, certain social groups (religious, professional,
  etc.).

The structure search


The term "search engine" is usually understood as a global, universal
search and will continue to question just about these systems. Schematic structure of most search engines is similar and there is no significant difference between them.



Interface

Seen by some search engine is a web site designed to interface to query the search engine. There also displays search results for a given query.

Software designed for indexing and retrieving information

• search algorithm;


• Database page addresses and information about Internet and intranet resources.

Search algorithm is an active part of the search engine, and his duties include:

• indexing of websites and their content;


• rank your websites and web pages;


• the formation of the search results.

The database (index) used for storing addresses of known search engine
sites and their pages, as well as the content, links or other
information contained on them.
The index is divided into chapters, and placed on multiple servers
distributed around the world (in the case of major search engines)
connected to the network.



Principles of how search engines work

Indexation

Search algorithm operates continuously, 24 hours a day scanning the
global network for new resources going after it finds, and links and
adding (indexing), the new addresses and information to the database
(index). Pages indexation should meet certain requirements concerning:

• uniqueness and quality (accuracy, the value of information and structure) content;


• the quantity and quality of links that the page;


• user activity on the site;


• lack of malware


• 
  Content compliance with certain requirements (for example, prohibiting
  the publication of materials breaking the law, incitement to terrorism);


• compliance with certain rules engine optimization.

Create a page ranking and displaying search results


In response to a user query, job searching an index search system scan,
find and offer you addresses of the parties, which is listed in your
search term, or a combination of the words as the key phrase. If you do not meet the key phrase query, the search engine chooses the side closest to the content.
As is usually the amount in accordance with the query page addresses is
very large, before the search is the task of laying the respective
ranking of those websites.
In other words, due to the fact that search algorithms must provide the
user with the opportunity to get acquainted with the most corresponding
query responses (which in practice is generally not possible because of
the very large quantities), the creator of the search engines took the
decision to display the results in the form of a structured ranked as
the Address Book, the leaders of which are sites with the best
performance, and further in the list are arranged side by deteriorating
indicators. Search results pages is a list of addresses. Furthermore, there is displayed a short text information content, the so-called snippets.



Penalties imposed by the search engines

If you find the job searching sites use to position the unlicensed technology, penalties may be imposed:

• lower position in the ranking;


• remove pages from the index, the so-called ban.

The technique permitted and may lead to the application by the search
engine penalties against parties are not limited to: Black SEO,
publishing unauthorized material, malware distribution, etc.



Priorities in the development of search engines

Search

The steadily growing number of pages wyszukującymi systems poses the
task of developing more and more new ways of organizing data and search
algorithms.
One solution developers search engines see the grouping of documents -
automatically creating multiple groups of semantically similar
documents.
At the same time, the criteria for selecting the groups are not known
in advance, but are determined automatically based on the similarities
observed to date.

Displaying the results

All search engines are geared up to present the widest base of answers to user questions.
Therefore, the search algorithms are improved in such a way that the
results formed the most appropriate query pages, the content of which is
the most interesting, well organized, unique and carrying a lot of
information.

Accurate and comprehensive results


Indices major search engines contain billions of addresses, and the
volume of information that can be found on their sites is hundreds of
thousands of gigabytes. In addition, the major search engines also offer the ability to search images, audio and video files.

Price performance

In addition to basic search algorithms, such as Panda on Google, the search engines also use more sophisticated algorithms. An example is the algorithm Fresh whereby Google constantly scans messages and can crawl them after a few minutes of the event.

Speed


The time needed to develop a search engine query and formulation of the
results is one of the most important parameters that determine how a
search engine, which their creators always try to minimize. At present, the rate of development of a single query in the leading search engines is approximately 1/4 second.