A Java Applet is a Java program that executes on the Web browser. Java Applets are limited to certain operations on the browser. Java applets can also use JDBC connection or distributed objects. The Java applet allows more complex user interface options than HTML combined with either CGI or Java servlets. However, the Java applet requires a Java-enabled Web browser.
Applets allow local validation of data entered by the user.
Local validation of data is possible using HTML combined with JavaScript but variances in JavaScript implementations make JavaScript difficult to generally use. An applet can use the database to perform list of values lookups and data validation. Once an applet is downloaded, the amount of data transferred between the Web browser and the server is reduced. Applets allow the designer to use complex GUI widgets such as grids, spin controls, and scrollbars. To see a Java applet in action, click here .