In 2015, Google created Accelerated Mobile Pages (AMP) technology.
The loading speed of the store changes due to:
- Google caches all AMP pages on CDN servers around the world for fast access
- Restrictions of AMP on uploaded files size leads to reduction of transferred data volume
- Limited use of js reduces the number of calls
For Shopify, a quick way to improve page loading speed is to install an app.
Google has published a review of AMP apps for Shopify.
In addition to the app, there is an option to use an AMP template. A simple example of a Shopify store built according to Google AMP is available at the link - pharmaboosters.com. Note the rating for mobile - 91 and for desktop - 100!