Recently I was working on a site remodel for a coaching client who had lost all the customization to her site after an update. She couldn't understand what had happened and why things looked so different. If her developer had taken advantage of the parent-child themes relationship this would have been a completely different scenario.
This problem could have been easily avoided if her original developer had used a child theme instead of making changes to the out of the box theme. The child theme would have preserved all of the custom coding that she paid for.
When I talked about the parent-child theme concept to the client, she felt lost because she isn’t overly tech savvy and had not a clue what I was trying to explain.
After a brief search of the terms, I was surprised that the results did not explain what the terms meant or answered questions about why this is important.
What is Framework?
Some people confuse themes and theme framework, and I one time I did too. While the terms are sometimes interchangeably, there is a difference.
According to WordPress Codex, the framework is a stand-alone theme designed to be the foundation for quicker WordPress development. Technically the stand-alone framework is the theme and can be used as is. The framework theme is also known as a parent theme.
In plain English: The framework separates the programming from the actual design which allows more speed and consistency for developers.
What is a Theme?
A standard theme is where all the design components reside with all the program files necessary to power the site in one package.
These themes have an options panel where you make changes to things like the logo, header, color options and such. The problem with themes is that when you do an update, you will overwrite all the customization work that has been done on your site.
See the way it works is when your theme has an update, the new files that contain the updates overwrite the original files. So if you have made changes to any of the code then it will be lost during the update.
What is a Child Theme?
WordPress Codex explains child themes as a theme that inherits the functionality of another theme, called the parent theme. Child themes allow you to modify, or add to the functionality of that parent theme.
In plain English: Same function and overall look as a parent theme with protection for customizations made to the site.
The whole idea of using a child theme is so that you can change pieces without modifying the parent theme. Because the parent theme is left intact, you don’t have to worry about losing hard work done to your site during updates.
Building the House
The easiest way for me to explain the relationship of WordPress to the parent and child themes is to relate it to building a house. WordPress is a framework or the foundation. You need to have a solid base on which to build the house of your dreams.
Your parent theme is similar to the structure including roof, walls, windows and utility hook-ups. All the pieces that go into making it a livable and functioning house. Your child theme is the decorations.
You will always have the same layout and rooms but if you want to add some pizzazz you can replace the carpeting, window dressings, and wall colors. Just like decorating your house, your child theme functions to match your style and brand.
When having a site designed or redesigned for you be sure to ask your WordPress web producer what theme framework they use and if they create child themes as part of the design process.