What is the information system?
Information system is a computer application system providing information services, technically four characteristics: large volumes of data, data persistently stored, to a database search CRUD other operations, data sharing.
Overall, the information is a system for storing the input data, processing results and useful information processing system for outputting to the user.
Three-tier structure of the software architecture which is divided into three layers? What is the function of each layer is briefly?
Three-layer structure is a client / server architecture, three layers are: presentation layer (user interface, human-computer interaction is mainly used), the application layer (business logic / data access), data layer: data storage.