If you canít find an existing WordPress theme that fits your needs or would like to create a unique style, you can use a custom theme. This is a theme you create from scratch or have someone create for you.

WordPress themes consist of CSS, HTML, and the PHP tags that serve as placeholders for dynamic content. Advanced users who are comfortable with these programming languages can build their own custom themes.

A custom theme must include styles for the following elements:

These styles go in a new file named style.css. This file is called the stylesheet. Each theme’s stylesheet must include a header that provides details about the theme. A theme also requires a functions.php file, which defines the functions that users can perform with it.

You can save time by using the Custom Theme Options plugin to handle your siteís copyright text, social media links, and more. Once youíre finished, you can choose to share your theme with others by submitting it to the WordPress Theme Directory.

/*
Theme Name: Twenty Thirteen
Theme URI: http://wordpress.org/themes/twentythirteen
Author: the WordPress team
Author URI: http://wordpress.org/
Description: The 2013 theme for WordPress takes us back to the blog, featuring a full range of post formats, each displayed beautifully in their own unique way. Design details abound, starting with a vibrant color scheme and matching header images, beautiful typography and icons, and a flexible layout that looks great on any device, big or small.
Version: 1.0
License: GNU General Public License v2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html
Tags: black, brown, orange, tan, white, yellow, light, one-column, two-columns, right-sidebar, flexible-width, custom-header, custom-menu, editor-style, featured-images, microformats, post-formats, rtl-language-support, sticky-post, translation-ready
Text Domain: twentythirteen

This theme, like WordPress, is licensed under the GPL.
Use it to make something cool, have fun, and share what you've learned with others.
*/

The stylesheet header in the style.css file for the theme “Twenty Thirteen.” The header must include unique details about the theme.