What is e-mail?

Electronic mail or e-mail is the service in computer network for sending the text document by data transmission.

What is Message?

They are information encapsulated in a frame or packet and sent from one entity to other. Receiving entity opens the packet and retrieve information from it. Communication between two distant entities are done through message passing.

What is ISP?

Interface Service Provider. The entities in a layer n interface implement a service used by layer n+1. In this case layer n interface is called interface service provider.

What is Entity?

OSI model divides a pc network into seven distinct levels. The active events in each layer will often be called entities. An entity is usually a software entity or a computer hardware entity.

What is meant by the Term System? What are the characteristics and categories of information system?

A system is an orderly grouping regarding independent components linked together based on a plan to achieve a certain objective. Here components means actual parts, managerial steps or a subsystem in a multilevel structure. An information system is efficient at providing end users with 3 kinds of information. They are transaction processing system, management reports and decision support system. Transaction processing would be the means by which most data is captured. There are two kinds of transaction, input and output. Management reports fulfill the defined information needs of supervisors. Four types of reports may be produced. They are detailed, historical, summary and exception reports. Each report is constructed from the data that are harnessed and stored during transaction digesting. Decision support system provide end users have real profit obtain needed information when a decision making situation arise. Expert systems are extensions of DSS.