The beauty of WordPress, the part that makes me love it so much, is the ability to customize pretty much any piece of a theme to your heart’s content. The downside however, is if the appropriate steps aren't followed, you’re in for a world of headache and trouble down the road. This is where the role of WordPress child themes become important. While there are countless amazing WordPress themes that can be used straight out of the box without changing a thing, I still have made core changes to every single site I've developed for one reason or another. You may be thinking “Well, so what? What’s going to happen…?”
The Problem Is Down The Road
When an update for a theme is released, you always want to install and apply it. Not only does it include new features or bug fixes, but often security upgrades are included protecting your website from malicious attacks. But, what happens to the changes? By installing the updated version of the theme, it’s telling WordPress to style everything based on the theme as is. If any changes to files have been made, including the CSS for things as simple as color changes, every customization will be overwritten. Imagine having to completely redesign and configure a site with EVERY update!
Sounds scary and troublesome, doesn't it? Don’t worry, that is where a WordPress child theme comes in. A child theme, when taken down to brass tacks, is a copy of the essential files of a theme that can be edited and customized without ever losing any changes when the parent theme is updated.