JavaServer Pages Standard Tag Library-

it’s a standard library of ready made tags.

Classification of jstl-
1- Core Tags
2- Formatting Tags
3- Sql Tags
4- Xml tags
5- Jstl functions

Tags	Description	Example
Core Tags	These tags are used to control the flow and structure of a JSP page. Examples include <jsp:include> and <jsp:forward>.	<jsp:include page="header.jsp" />
Formatting Tags	These tags are used to format and display data on a JSP page. Examples include <c:out> and <fmt:formatNumber>.	<c:out value="${user.name}" default="Guest" />
SQL Tags	These tags are used to interact with a SQL database. Examples include <sql:query> and <sql:update>.	<sql:query var="result" dataSource="jdbc/myDB">SELECT * FROM users</sql:query>
XML Tags	These tags are used to interact with XML data. Examples include <x:parse> and <x:out>.	<x:parse xml="data.xml" var="data" scope="page" />
JSTL Functions	These functions provide commonly used operations such as string manipulation, mathematical operations and conditional evaluations. Examples include fn:length() and fn:substring().	<c:out value="${fn:length(user.name)}" />