TYPES OF ENVIRONMENTS
There are 4 types of environments:
1. STAND-ALONE ENVIRONMENT (OR) ONE-TIER ARCHITECTURE.
2. CLIENT-SERVER ENVIRONMENT (OR) TWO-TIER ARCHITECTURE.
3. WEB ENVIRONMENT (OR) THREE-TIER ARCHITECTURE.
4. DISTRIBUTED ENVIRONMENT (OR) N-TIER ARCHITECTURE.
1. STAND-ALONE ARCHITECTURE:
In this environment all the three layers that is presentation layer, business layer, database layer will be available in the single tier. When the application needs to be used by a single user at a time then one can suggest this environment.
Ex: Personal Computer.
2. CLIENT-SERVER ENVIRONMENT:
In this environment two tiers will be there. One is for clients, other is for servers. Presentation layer and business layer will be available in each and every client; database layer will be available in the server.
Whenever the application need to be used by multiple users sharing the common data in a single premises and wants to access the application very fastly and there is no problem with security. Then one can suggest client- server environment.
Ex: LAN
3. WEB ENVIRONMENT:
This environment contains three tiers. One is for clients, middle one is for application server and the last one is for database servers.
Presentation layer will be available in client, Business layer will be available in the application server and Database layer will be available in the database servers.
Whenever the application needs to be used all over the world by limited number of people then this environment can be suggested.
Ex: WAN.
4. DISTRIBUTED ENVIRONMENT:
This environment is similar to web environment but number of application servers are introduced in individual tiers. In order to distribute the business logic, so that load will be distributed and performance will be increased.
Whenever the application needs to be used all over the world by huge number of people then this environment can be suggested.
Ex: yahoo.co.in, yahoo.co.uk, yahoo.co.us….etc.
DATABASE: It is a base (or) a place where on can store and retrieve the data