Client Server Architecture

 Client-server architecture is a system that hosts, delivers, and manages most of the resources and services that the client requests.  

              How the client-sever model work?

• Client: when we talk the word client, it mean to talk of a person or an organization using a particular service. Similarly in the digital world a Client is a computer(Host) that is capable of receiving information or using a particular service from the service providers(Servers).

• Servers: similarly we talk the word Servers, it means a person or medium that serves something. Similarly in this digital world a Server is a remote computer which provides information(data) or access to particular services.

• So, its basically the Client requesting something and Server serving it as long as it present in the database.

 

Client-server Communication Process

• Request: requests are sent from the client tot he server to inform it of events, such as a user wishing to log in using credentials or to ask the server for data, such as files.
• Response: A server's response to a client request is sent to the client as a message. This might, for instance, be the outcome of an authentication.
• Server: a particular task the server makes available to the client for use, such as downloading an images.

Types of Client-Server Architecture

1. 1-Tier Structure

• The user interface, business logic and data logic are present in same system.
• This kind of client server service is cheapest but it is difficult to handle because of data inconsistency that allows repetitive of work
• Ex: The MP# player and MS Office files.

2. 2-Tier Structure

• user interface is stored at client machine and database are stored on server.
• Database logic and data logic are either stored at client or server but it must be unchanged.
• If Business Logic and Data Logic are stored at client side, it is called fat client thin server architecture.
• If Business Logic and Data Logic are stored on server, it is called thin client fat server architecture.
• This kind of architecture are affordable and comparatively better.
• It is typically used in small environments.
  

3. 3-Tier structure

• it is an additional middle-ware is used that means client request goes to server through that middle layer and response of server is firstly accepted by middle-ware then to client.
• This architecture overcome all the drawbacks of 2-tier architecture  and gives best performance.
• It is costly and easy to handle
• It has 3 layers: application layer, presentation layer and database layer

Advantages of Client-Server Architecture

1.  Centralization: a single server that houses all of the essential data in one location makes data security and user authorization and authentication control much easier.

2. Scalability: a client-server network may be expanded by adding segments, servers, and PCs with little downtime. The number of resources, such as clients and servers, can be increased as needed by the user. Consequently, the server's size may be increased without disruption.

3. Easy Management: client and server do not have tot be close to access data effectively. It is simple to handle files because they are all kept on the same server. The finest management for tracking and finding record of necessary files is offered in client-server network.

4. Accessibility: the client-server system's nodes are all self-contained, requesting data only from the server, allowing for simple upgrades, replacements, and relocation.

5.Data Security: the centralized design of client-server network ensures that the data is properly safeguarded. Access controls can be used to enforce it and ensure that only authorized users are allowed access. If the data were to be destroyed, it would be simple to restored the files from a single backup.

Cloud Computing 

It is delivery of computing services including servers, storage, databases, networking, software, analytics, and intelligence over the internet(the cloud) to offer faster innovation, flexible resources, and economies of scale.

Rather than keeping files on a proprietary hard drive or local storage device, cloud-based storage makes it possible to save them to remote database. As long as an electronic device has access to the data and  the software programs to run it.

Cloud computing is popular option for people and businesses for a number of reasons including cost savings, increased productivity, speed and efficiency, performance, and security.

Types of cloud Computing

Cloud computing is not single piece of technology like a microchip or a cellphone. Rather, it is a system primarily comprised of three services: 

1. software-as-a-service(SaaS): involves the licensure of a software application to customers. this type of system can be found in Microsoft Office's 365.

2. Infrastructure-as-a-service(IaaS): involved a method for driving everything from operating systems to servers and storage through IP-based connectivity as part of an on-demand service. Ex: IBM cloud and Microsoft Azure.

3. Platform-as-a-server(IaaS) is considered the most complex of the three layers of cloud-based. PaaS shared some similarities with SaaS, the primary difference being that instead of delivering software online, it is actually a platform for creating software that is delivered via the internet.