What are themes and how do they work?

- Themes control the appearance of your WordPress site on the front-end, so what people see when they visit your site. But how do they work? Understanding the basics of theme construction will make it easier for you to find a theme that fits your site, and troubleshoot your theme when things don't work as expected. A WordPress theme is a series of templates, style sheets, and script files contained within a dedicated folder. When you add a new theme to your WordPress site, you're actually just adding a new folder to the themes folder in your installation. WordPress automatically recognizes the theme, and makes it available to you.

The templates in your theme are based on something called the WordPress Template Hierarchy. Now, you don't have to know how this works exactly, you just need to know it exists. It's a system the application uses to pick the right template for the right type of content. In simple terms, a theme works like this: A browser is told to visit a URL that points at a specific database entry. So you see, here, we have a standard human-readable URL that the computer will interpret as a database entry, in this case, 1706.

We then go to the database and find the entry for 1706, and recognize that this is a post. Then, WordPress will go to the theme, and grab the single.PHP template, which is the template for regular posts, pop up the template, and find what's necessary, then pull the content that's necessary, so in this case, the post title, and place it into the post title area within the template, and finally build the page. This is the process that takes place every time someone visits your site. And all of this happens in a fraction of a second.

The themes applies all the components to make up a view: The header, the main content area, the sidebar, the footer, and all of it ties together seamlessly in the browser so it looks like one cohesive page. This is why you can configure a header image, a main menu, and sidebar widgets independently, and why some themes will display different headers or sidebars, and other content depending on what you're looking at. Your theme is like a Lego kit, and the theme designer and developer has put it together to best reflect the different types of content on your site.

Your job is just to pick the right kit, and the right theme.