Introduction

A client is a part of a distributed application that communicates with another part of this application called a server, in order to consume services it provides. The server, on the other hand, is a part of distributed application that passively waits for requests arriving from clients. When a request arrives, the server performs the requested operation and sends a response—the result of the operation—back to the client.

The key characteristic of a client is that it needs a service provided by the server and it initiates the communication session with that server in order to consume the service. The key characteristic of the server is that it serves the requests coming from the clients by providing a requested service.

We'll consider servers in the next chapter. In this chapter, we are going to focus on client applications and will consider several types of them in detail.

The classification of client applications

Client applications can be classified by the...