Client-server model

Previously, network systems were based on a centralized computing model in which one powerful server - the mainframe - did the main work on the network, and users accessed it using inexpensive and low-performance computers - terminals. As a result of the development of personal computers, the centralized model has been replaced by the client-server model, which provides network processing capabilities with the same performance.

As a result of the development of personal computers, the centralized model has been replaced by the client-server model

Currently, most networks use the client-server model. A client-server network is a network environment in which a client computer initiates a request to the server computer that makes the request. Let's consider the operation of the client-server model on the example of a database management system - an application often used in a client-server environment. In the client-server model, the client software uses Structured Query Language (SQL), which translates a query from a language that the user understands to a language that the machine understands. SQL is close to natural English.

The client (user) generates a request using a front-end application that provides a user interface, generates requests, and displays data received from the server.

In the client-server model, the server is not endowed with a user interface. The client himself is responsible for presenting data in a convenient form. The client computer receives instructions from the user, prepares them for the server, and then sends a request to it over the network. The server processes the request, searches for the necessary data and sends it to the client. The client displays the received information in a user-friendly form. In the client-server model, the user of the client computer deals with a screen form. In it, he sets the necessary information parameters. The interface part can represent the same information in different forms.

The server in the client-server model is usually designed to store and manage data. It is the server that performs most of the data operations. The server is also called the application part of the client-server model, since it is he who fulfills the requests of clients. Data processing on the server consists of sorting them, extracting the requested information and sending it to the user's address. The software also provides for updating, deleting, adding and protecting information.

Client-server technology creates a powerful environment with many real benefits. In particular, a well-planned client-server system provides a relatively inexpensive platform that still has the computing power of a mainframe and is easily customizable for specific tasks. In addition, in the client-server model, network traffic is drastically reduced, since only the results of requests are sent over the network. File operations are mostly done by a more powerful server, so requests are better served. This means that the load on the network is distributed more evenly than traditional file server based networks. Reduces the need for client computers in RAM, since all work with files is performed on the server. For the same reason, disk space requirements are reduced on client computers. Simplified system management, control of its security becomes easier, since all files and data are hosted on the server. Simplified backup.