I must have seen the scenario a hundred times, and it always ends in tears and frustration. You choose a nice looking theme from Theme Forest or somewhere similar, and then get a developer to install it and cusomise the design to suit your needs.
A few months later, the theme releases and update. You click on it and Boom.
The site looks like your cat designed it and all the customisation have been erased.
You have to restore a backup, or get it all done again.
When you edit a theme, these edits will be written over when the theme updates are installed.
Child themes avoid this issue, by being a seperate file from the parent theme which contains all the edits.
All the edits live in the child, and the parent theme is unchanged. Then when the parent theme is updated, these edits still apply to the updated theme.
Using a framework theme like Genesis makes this even smoother and more stable to create custom designs, as it has been designed for this parent-child theme setup.
And let’s face it, you never like those pre-made themes exactly as they come.
