To help with the processing of large data sets - information retrieval systems.

In a modern world filled with information, it is sometimes extremely difficult to find the right data, classify it, analyze, compare and process it. Fortunately, modern achievements of civilization can help in this difficult work. These are information retrieval systems, each of which is an applied computer environment designed for searching, storing, processing, filtering, sorting, large arrays of structured data.

A simpler definition, which is often used when describing information retrieval systems, sounds like this. Information retrieval systems are systems capable of providing search and selection of necessary information by using a special database that contains descriptions of data sources (index) based on the information retrieval language. The search for information in such systems must be carried out according to certain rules corresponding to the information retrieval language. One of the most widely used and used in RuNet information retrieval systems is nigma ru algebra.

Information retrieval systems are divided into two types:

1. Documentometric. This type of system is characterized by the fact that each document stored in them must be indexed in a special way. In other words, each of the documents has a special code, which makes up the search image. Search is carried out by search images, and not by the documents themselves. This principle resembles the search for a book in a large library. Initially, you need to find a card in a special directory, and then, knowing the number indicated on the card, it becomes possible to calculate the location of the book itself.

2.Factographic. Such information retrieval systems store facts concerning a certain field of knowledge, and not documents confirming them. Search is organized exactly on the basis of a certain fact.

The main task successfully solved by information retrieval systems is the search for data relevant to information requests and users' needs. An extremely important aspect of working with systems is the absence of lost data, that is, it is necessary to find each document that relates to the query and not find any unnecessary information. To implement this requirement, introduced a qualitative characteristic of the search process - relevance. Relevance is the correspondence of the results obtained during the search to the query that was formulated.

The main purposes, pursuing which are developed by traditional information retrieval systems are somewhat. So, it is necessary:
- provide translation of the natural language used in the documents for the controlled dictionary, applicable for search and indexing;
- ensure consistent use of index units;
- describe the relationship between terms;
- use the system as a search tool when searching for documents.

A little more detail on the service, which has gained immense popularity - nigma mathematics. This system gives its users the opportunity to solve mathematical problems. Among the possibilities of the system is the simplification of mathematical expressions, the solution of equations, systems of equations, and much more. All this is done in automatic mode after entering an expression into the search string. The system is equipped with the ability to recognize more than a thousand mathematical and physical units of measurement and constants, and this allows the user to operate with different values. The answer given by the system in this case will exactly correspond to the indicated units of measurement. In addition, through the nigma mathematics system, you can solve any task usually imposed on calculators and currency converters.