As developers have created more and more custom tag libraries, they discovered a need to come up with a standard library of the most commonly used ones. This led to the Java Standard Tag Library standard (JSTL).
JSTL can be broken up into a number of large sections. Each one will be briefly summarized in the following sections.
The general purpose tags are c.out, which writes a value to the JSP stream; c.set, which sets a scoped variable; c.remove, which removes a scoped variable; and c.catch, which is used to catch exceptions inside its body.
The conditional action tags implement control flow. c:if is a straightforward conditional evaluation, whereas c:choose in ...