Hibernate is an ORM tool. It will be better if you learn it along with JDBC. But,also one more thing if you are more interested towards learning Spring & Hibernate only then you can learn the basic concepts regarding Servlets & J2EE and then you can kick-start with Spring. Learn Servlets and JSP - Head First is good.

What is the difference between JSP and servlet? JSP (JavaServer Pages) is a technology that allows embedding Java code into HTML pages, while servlets are Java classes that handle requests and responses on the server-side. Servlets are pure Java, whereas JSP combines Java code and HTML for dynamic web page generation.

A servlet is a Java programming language class that is used to extend the capabilities of servers that host applications accessed by means of a request-response programming model. Although servlets can respond to any type of request, they are commonly used to extend the applications hosted by web servers.

In this mode, JSP pages are used for the presentation layer, and servlets for processing tasks. The servlet acts as a controller responsible for processing requests and creating any beans needed by the JSP page. The controller is also responsible for deciding to which JSP page to forward the request.

If the same servlet receives several requests, only one thread will be started for each request.

After communicating with the database or carrying out any other actions, the servlet processes the request object, prepares the response object, and then delivers the response object back to the web server