<body <?php body_class(); ?>>
<body>: Represents the opening tag of the body element in HTML, defining the main content of the document.<?php ... ?>: Indicates the opening and closing tags for embedding PHP code within HTML.body_class(): A WordPress function that outputs a set of CSS class names for the body element, based on the current context and page attributes.<?php body_class(); ?>: Embeds the dynamically generated CSS class names within the body tag to apply styling based on the specific characteristics of the WordPress page being viewed.