Alternative PHP PPA repository

[Rafagd]

I'm writing a Dockerfile to generate a qloapps/hotelcommerce image that only contains the application itself instead of App+Database like the one provided in the website. While rearranging the apt-gets into a separated RUN instruction to allow for caching of that section of the installation process, I've stumbled with a line that adds this PPA "ppa:ondrej/php" which downloads a custom version of PHP different of the one provided by the Ubuntu maintainers.

Is there an specific reason why that is required or could I just run it with the Ubuntu-provided package?