Question

In web programming what is the Client-Server model?

Answer 1

As quoted by Wikipedia "Client–server model is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients".

definations:

Server-A server is a computer program or device that provides a service to another computer program and its user

Client-A client is a computer that connects to and uses the resources of a remote computer, or server.

LAN-A local-area network (LAN) is a computer network that spans a relatively small area

WAN-A wide area network (WAN) is a telecommunications network that extends over a large geographical area for the primary purpose of computer networking.

TCP/IP-The TCP/IP Model separates networking functions into discrete layers. Network models are used to conceptualize how networks should work, so that hardware and network protocols can inter-operate.

CLIENT-SERVER IN WEB PROGRAMMING;

Widely used client-server model is based on computer transactions in which the server fulfills a request made by a client.In this context, the client establishes a connection to the server over LAN(local area network) or or wide-area network (WAN), such as the Internet.

The client-server model is also a core network computing concept and a building functionality for email exchange and Web/database access. Web technologies and protocols built around the client-server model are:

• Hypertext Transfer Protocol (HTTP)-used by the World Wide Web and this protocol defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands.
• Domain Name System (DNS)- is the phone-book of the Internet i.e if you enter a address(eg -www.google.com) then it will take you to google server.
• Simple Mail Transfer Protocol (SMTP)-is a set of communication guidelines that allow software to transmit an electronic mail over the internet
• Telnet- telnet is a user command and an underlying TCP/IP protocol for accessing remote computers

An important advantage of the client-server model is that its centralized architecture helps make it easier to protect data with access controls that are enforced by security policies. Also, it doesn't matter if the clients and the server are built on the same operating system because data is transferred through client-server protocols that are platform-agnostic. Commonly used data methods includes JSON(java-script object notation), XML( eXtensible Markup Language).

An important disadvantage of the client-server model is that if too many clients simultaneously request data from the server, it may get overloaded. In addition to causing network congestion, too many requests may result in a denial of service.

At last we can simply define client-server model as

• client sends a request
• server process the request and send the respective data
• client again receive the data and render it on the screen