The JSTL <c:import> tag is used to include the contents of an external resource, such as a JSP page or a static HTML file, in the current JSP page. This tag is part of the JSTL core tag library, and is typically used to include common HTML elements or JSP fragments across multiple pages.

The basic syntax for the <c:import> tag is as follows:

<c:import url="resource" [var="name"] [scope="scope"] [charEncoding="encoding"] />

The url attribute of the <c:import> tag is used to specify the URL of the resource to import. This attribute is required.

The optional var attribute can be used to store the contents of the imported resource in a variable, and the optional scope attribute can be used to specify the scope of the variable (e.g., page, request, session, or application). If the var attribute is not specified, the contents of the imported resource will be sent directly to the output stream.

Here's an example that shows how to use the <c:import> tag to include the contents of a JSP fragment in a larger JSP page:

<c:import url="/fragments/myFragment.jsp" />

In this example, the <c:import> tag is used to include the contents of the file "myFragment.jsp", which is located in the "fragments" directory of the web application. The contents of this file will be included in the output of the current JSP page.

Note that the <c:import> tag can also be used to include static HTML files, as well as resources from other web applications or remote servers. The <c:import> tag provides a number of other optional attributes for controlling the behavior of the tag, such as context, which can be used to specify the context root of the web application containing the resource to import.