The following article explains What is a Servlet.

A servlet is a program in Java that runs on a web server and provides dynamic web content. Also, servlets work on the server side and can handle client requests and generate responses accordingly. Servlets are used for creating web applications that are scalable, reliable, and platform-independent.

Servlets follow the Java Servlet API specification. They are typically used to implement server-side logic for web applications, such as processing form data, accessing databases, and generating dynamic HTML pages.

Servlets are written in Java and run in a web container that provides a runtime environment for the servlets. The web container manages the lifecycle of the servlets, handling HTTP requests and responses, and providing other services to the servlets. Popular web containers that support servlets include Apache Tomcat, Jetty, and IBM WebSphere.

Further Reading

Spring Framework Practice Problems and Their Solutions

Java Practice Exercise