Search engines are software systems that use sophisticated technology to locate information on the Internet. Using highly complex algorithms, they scour billions of pages for information related to various URLs (Uniform Resource Locators). There are several sub-categories of search engine software including web search engines, database search engines and mixed search engines.
The most popular and powerful search engines are web based systems that gather information from across the Internet. These are accessed via a web browser by entering a question into a search box. A list of relevant information is then returned.
Most searches are based on keywords, which are words or phrases that are used to describe an object or concept. Search engines rely on a process called natural language processing to understand and interpret the question and produce a list of related websites that contain information about that topic.
A key element of the process is to identify and rank websites based on their popularity and relevance to the question. The search engine algorithm also evaluates a variety of other elements to determine the importance of each page that is returned in the results. These include the keywords found on a page, how many other pages link to it and how well the content of a page matches up with the search query.
To make sure that they provide the best possible answers to questions, modern search engines are constantly evaluating their own processes and algorithms to make improvements. This is known as SEO, or search engine optimization. This is a highly competitive field and successful websites must be designed to appeal to both humans and the online search engine “spider” algorithms. Attempts to manipulate a website’s ranking by using unnatural or artificial methods are considered black hat techniques.
Search engines have become more sophisticated in identifying pages that are simply stuffed with keywords to achieve higher rankings. They are also avoiding pages that are purely commercial or political in nature. Search engines also avoid displaying websites that violate the terms of service for a given search engine.
It is important to remember when performing a search that the results are only as good as the quality of the query itself. A poorly written search query will return many irrelevant or incorrect results. Using a few simple Boolean search techniques can help improve the effectiveness of a query.