Distributed computing is nothing but computing performed in a distributed system. Programs running on independent computers cooperate with each other to perform computing such as network services and Web-based applications. Network service is provided by a program called server on a network.

World Wide Web is such a network service. A network application runs on networked computers for end users. Online shipping carts and electronic auction sites, chat rooms and network games are some of the network applications.

Advantages

Affordability of computers and availability of network access.

Nowadays personal computers are cheap but they have more computing power than old mainframe systems. Moreover access to Internet is not only easily available but also affordable. So large number of computers can be interconnected to make distributed computing powerful.

Resource sharing

Organizations can use distributed computing to pool their resources effectively.

Scalability

More resources can be added to network if the demand increases.

Fault tolerance

Fault tolerance is achieved by replicating the resource. Replication ensures that the required
resource is available when there is a failure.

Disadvantages

Multiple points of failure

Failure of one or more computers or network links can disturb the function of distributed computing system.

Security concerns

As the management is decentralized there is a great chance of unauthorized attack. Decentralization poses challenges to implement and enforce security polices thereby making the system vulnerable to security breaches and unauthorized access.