Meaning – The term servlet, refers to An application program, written in the Java programming language, that is executed on a Web server. A reference to a servlet appears in the markup for a Web page, in the same way that a reference to a graphics file appears. The Web server executes the servlet and sends the results of the execution (if there are any) to the Web browser.
It is similar to an applet but is processed on the server rather than a client machine. Servlets are often run when the user clicks a link, submits a form, or performs another type of action on a website.
Both servlets and JSP pages contain Java code that is processed by a Web server. However, servlets are primarily Java programs, while JSP pages are primarily HTML files.
Example of usage – “Servlets are one of many options Web developers can use to create dynamic websites and process data entered by website visitors. Since they are written in Java, servlets provide an easy way for programmers who are already familiar with the Java programming language to create Web applications.”