What is client-server architecture?


Before we explain the client-server architecture and you start reading words like servers, service, network, data, and files and start feeling overwhelmed by the jargon, first understand this architecture.
 
Client-server architecture can be understood as an analogy for placing an order of pizza for delivery. You call the store to request a pizza, and someone picks up the call, takes your order, and then delivers it. Simple, right? Yes, this analogy pretty much matches the basic principle of client-server architecture.
Simply put, two factors are involved:
 
" The server is the one that supplies the requested services.
" Clients are those who request services.
 
A client-server architecture is a computing model in which the server hosts, supplies, and handles most of the resources and favors requested by the client. It is also known as the network computing model or client-server network because all requests and services are delivered over the web. A client-server architecture or model has other systems connected over a network where resources are shared between different computers.
 
Typically, a client-server architecture is arranged, so clients are often located on workstations or personal computers. At the same time, the servers are located elsewhere in the network, usually on more powerful machines. Such a model is particularly advantageous when clients and servers perform routine tasks. For example, the client's computer may be busy running an application program to enter patient information while processing hospital data. Meanwhile, the server computer can run another program to retrieve and manage the database in which the information is permanently stored.
 

Characteristics of the client-server architecture


A client-server architecture is typically characterized by the following characteristics:

" Client and server machines usually demand different hardware and software resources from other vendors.

" The network has horizontal scalability that increases the number of client computers and vertical scalability and then moves the       whole process to more effective servers or a multi-server configuration.

" A single computer server can provide multiple services simultaneously, but each requires a separate server program.

" Both client and server applications communicate directly with the transport layer protocol. This process establishes communication    and permits entities to send and accept information.

" Both the client and server computers require a whole set of protocols. The transport protocol uses lower-layer protocols to send     and receive individual messages.
 

What are examples of client-server architecture?


You may be wondering what constitutes a real application of client-server architecture. Here are three examples of client-server architecture, probably more often than you think!

Email Servers: Due to its simplicity and speed, email has supplanted traditional postal mail as the primary form of business communication. Email servers, supported by various brands of specialized software, send and receive emails between parties.

File servers: If you store files in cloud services like Google Docs or Microsoft Office, you are using a file server. File servers are centralized locations for storing files accessed by numerous clients.

Web Servers: These high-performance servers host multiple websites and are accessed by clients over the Internet. Here is a detailed breakdown:

" The client/user utilizes their web browser to enter the requested URL
" The browser requests the Domain Name System (DNS) for an IP address.
" The DNS server discovers the IP address of the requested server and sends it to the web browser.
" The browser will create an HTTPS or HTTP request.
" The server/producer sends the correct files to the user.
" The client/user accepts the files transmitted by the server, and the process reiterates as needed.
 

Components of the client-server architecture:


Essentially, three components are required for a client-server architecture to work. These three components are workstations, servers, and network devices. Let us now debate them in detail:

Workstations: Workstations are also called client computers. Workstations are subordinate to servers and send requests to access shared files and databases. The server requests information from the workstation and performs several functions as a central repository for files, programs, databases, and management policies. The workstation follows the guidelines defined by the server.

Servers: Servers are defined as high-speed processing devices that act as centralized storage of network files, programs, databases, and policies. Servers have massive storage space and robust memory to simultaneously handle multiple requests from different workstations. Servers can simultaneously perform many roles in a client-server architecture, such as mail server, database server, file server, and domain controller.

Network Devices: Now that we know the roles that workstations and servers play, let's learn what connects them, network devices. Network devices are the medium that connects workstations and servers in a client-server architecture. Many network devices are used to perform various network operations. For example, a hub connects a server with multiple workstations. Repeaters are used to efficiently transfer data between two devices. Bridges are used to separate network segmentation.
 

Types of client-server architecture


The functionality of the client-server architecture is in different layers.
 
1-tier architecture
In this category of client-server architecture, the architecture includes all kinds of settings, such as configuration settings and marketing logic, on a single device. While the variety of services offered by a single-tier architecture makes it one of the reliable sources, manipulating such an architecture is difficult. The reason is primarily the difference in data. It often leads to replication of work. A single-tier architecture combines several layers using a particular software package, such as the presentation, business, and data layers. The data that exist in this layer is often stored on local systems or on a shared disk.
 
2-tier architecture
This architecture has the most appropriate surroundings. In this, the user interface is stored on the client side, the database is stored on the server, while the database logic and business logic are maintained either on the client or server side.
 
The 2-tier architecture is faster compared to 1-tier architecture; this is because the two-tier architecture has no intermediate between the client and the server. It is often used to avoid confusion between clients. One famous example of two-tier architecture is an online ticket booking system.
Career transition
 
3-tier architecture
Unlike a 2-tier architecture without an intermediary, 3-tier client-server architecture has a middleware between the client and the server. If a client makes a request to retrieve specific information from a server, the request is first received by the middleware. It will then be sent to the server for further action. The same pattern will be obeyed when the server transmits a response to the client. The 3-tier architecture framework is divided into three main layers: presentation, application, and database.

All three layers are handled at various ends. While the presentation layer is held on the client device, the middleware and server handle the application and database layers. Due to a third layer that ensures data control, the 3-layer architecture is more secure, has an invisible database structure, and provides data integrity.
 
N-layer architecture
N-tier architecture is also called multi-tier architecture. It is a reduced form of the other three types of architecture. This architecture has provisions for placing each function as an isolated layer, including presentation, application processing, and data function management.
 
 

Advantages and disadvantages of client-server architecture


Client-server architecture conveys its share of positives and negatives to today's digital consumers. Let's start with a list of benefits:

" It is a centralized system that keeps all data and controls in one zone.
" It conveys a high level of scalability, organization, and efficiency.
" Allows IT staff to independently change client and server capacity.
" It is cost-effective, especially when it comes to maintenance.
" Enables data recovery.
" Enables load balancing, which optimizes performance.
" It allows different platforms to share resources.
" Users do not require to log on to a terminal or processor to access corporate information or desktop tools such as PowerPoint              presenters or spreadsheet tools.
" The setting reduces the occurrence of data replication.

Naturally, client-server architecture is not all sunshine and lollipops. Here are the cons:

" If a server has a worm, virus, or Trojan, users will likely catch it because the network consists of connected clients and servers.
" The server is vulnerable to DoS (Denial of Service) attacks.
" Data packets can be copied or modified during transmission.
" Startup and initial implementation are costly.
" Clients are dead in the water if a critical server fails.
" The setup is vulnerable to phishing and Man in the Middle (MITM) attacks.
 

Conclusion


This article described how networking is the act of forming strategic alliances through communication and data exchange with other individuals, computers, or organizations. The client-server architecture is part of a network model that allows updates for multiple users via a graphical user interface to a transmitted database. Organizations, large or small, use networks to scale and digitalize their businesses, market their products, and enhance their learning of news and events in their specific industries.