Wordpress in image url    || ||     <?php echo get_template_directory_uri(); ?>
sample  =>    <img src="<?php echo get_template_directory_uri(); ?>/images/snack.png" alt="snack">

Wordpress in a tag url    || ||     <?php echo esc_url( get_home_url() ); ?>
sample  =>    <a href="<?php echo esc_url( get_home_url() ); ?>/rest.php">more</a>

Wordpress in css url      || ||     <?php echo get_template_directory_uri();?>
sample  =>    <link rel="stylesheet" href="<?php echo get_template_directory_uri();?>/css/import.css" >

Wordpress in js url       || ||     <?php echo esc_url( get_template_directory_uri() ); ?>
sample  =>    <script src="<?php echo esc_url( get_template_directory_uri() ); ?>/js/jquery.js"></script>