JSP Expression Language

• JSP Expression Language

JSP Expression Language (EL) makes it possible to easily access application data stored in JavaBeans components. JSP EL allows you to create expressions both (a) arithmetic and (b) logical. Within a JSP EL expression, you can use integers, floating point numbers, strings, the built-in constants true and false for boolean values, and null.

http://www.tutorialspoint.com/jsp/jsp_expression_language.htm

• Expression Language

A primary feature of JSP technology version 2.0 is its support for an expression language (EL). An expression language makes it possible to easily access application data stored in JavaBeans components. For example, the JSP expression language allows a page author to access a bean using simple syntax such as ${name} for a simple variable or ${name.foo.bar} for a nested property.
http://docs.oracle.com/javaee/1.4/tutorial/doc/JSPIntro7.html

• Expression Language in JSP 2.0

Expression Language was first introduced in JSTL 1.0 (JSP Standard Tag Library ). Before the introduction of JSTL, scriptlets were used to manipulate application data.JSTL introduced the concept of an expression language (EL) which simplified the page development by providing standerd tag libraries. These tag libraries provide support for common, structural tasks, such as: iteration and conditionals,
processing XML documents, internationalization and database access using the Structured Query Language (SQL).

The Expression Language introduced in JSTL 1.0 is now incorporated in JavaServer Pages specification(JSP 2.0).

http://www.javabeat.net/2007/08/expression-language-in-jsp-2-0/