The function of the WordPress page template allows you to build and customize your own web pages, every page template has a template name. Page templates can change the design and layout of a page and can be applied to a single page or be used globally across all pages. Page templates may also display a block of content. Page templates display your website’s images and words as dynamic content across your website. It can control the look and feel of individual pages and can apply to a single page, a page section or a class of pages. It will also allow you to show an image that links to another part or post on your WordPress website. The pages templates also enable you to start to customize each individual section of each page. You can also create your own templates and apply it across as pages, navigation systems, main content areas and the footers. All template files live within a theme and show how a site is displayed, they contain a mixture of HTML and PHP code.
Template tags are a custom built-in function into WordPress and are used to get certain chunks of content such as the header and the footer. Instead of copying and pasting the footer content code across all pages by adding to the index.php file the code of get_footer() within the PHP code. If you make a change to your footer file, it updates globally across all of your template pages within your site.