Search Engines

The Internet contains a gigantic amount of information. For this reason, finding useful information is not an easy task. This is where the search engines come into play. Without search engines, research tasks on the web would be doomed to fail from the start.

The search engine is therefore a program for researching documents that are stored on a computer or a computer network such as the World Wide Web. More than a thousand search engines around the world compete for the attention of internet surfers.

Most search engines work according to the same scheme. They create an index for the entered keywords in order to answer search queries with a hit list ordered by relevance. After entering a search term, the search engine returns a list of references to possibly important documents. These are usually shown with a title and a short excerpt of the respective document. Various search methods can be used for this.

The main tasks of a search engine are as follows:

• the creation and maintenance of a text-based index with information about the documents.
• processing search queries and finding and ordering results.
• The processing of the results in the most meaningful form possible.

Data indexing on the World Wide Web is usually done automatically by so-called web crawlers, which search the entire Internet for data and save all the data found in a database.