As we all know, Java is a programming language that’s used to build programs that can work on the local machine and on the internet as well. Its primary features are that it is object-oriented and a cross platform language. So there are various categories of programs that can be developed in Java.
An application is a program that runs on the computer under the operating system of your computer. Creating an application in java is similar to doing so in any other computer language. The application can either be GUI based or console based.
Console based applications are Java programs that run from a command prompt and do not display any GUI based screen. Such programs have console based outputs.
GUI based applications are the Java programs that run stand-alone and accept user input through a GUI based screen.
These are the applications which are web-based in nature and requires a web browser for execution. The Web applications makes use of a Server to store the data, and every time a user requests to execute that application, the request is passed on to the server for suitable reply.
Applets are Java programs that are created specially to work on the internet. They run through a Java embedded browser such as Firefox, Chrome, Internet Explorer, Netscape and many more. An applet can be created using any Java development kit or tool. To work it out through the internet, it must be contained or embedded within a web page or HTML file.
Examples of Java Applets include developing games, visual effects and so on.
Java is suitable for web based n-tier application development. In a web based application, the client sends a request to a server. The server processes the request and sends a response back to the client. The server side Java Application Programming Interfaces (APIs) takes care of the program process and the response of the client’s request. These server side APIs extend capabilities of standard Java APIs and are known as Java servlets (also known as server side applets). HTML form processing is one of the simplest uses of servlets. These servlets can also process databases and perform server side transactions. Servlets make use of web servers for their execution.
It requires a server to run these applications. A number of servers are used simultaneously for backup to prevent any data losses.
These are the programs that use the JDBC API for database connectivity. They could either be applets or applications, though applets may face security problems when dealing with databases.
CLIENT SERVER APPLICATIONS
These application too makes use of web technology for their execution. They follow simple Client-Server model, where a client makes requests directly to the server.