Servlets and Java Server Pages were proposed by Sun Microsystems.
They are very convenient for the Web, since they are portable, i.e., will
run on any machine on which Java Virtual Machine is available.
Servlets are classes written in Java, which adhere to a specific API.
The latest servlet specification is now 2.3.
Java Server Pages (JSP) are HTML pages which contain special tags.
These tags represent Java source code. The JSP page is processed through
a special processor which converts it to a source code of Java servlet class.
Then the servlet source is compiled. And finally, the servlet
is executed. The latest servlet spec is 2.3, and JSP spec is 1.2.
Before talking about servlets/JSP we need to have a few words about