Most sites will use some form of analytics software to gain insights into how the site is being used. There are many modules in Drupal to support the inclusion of tracking softare on the site. Common mosules for this include Google Analytics, Google Tag Manager and Matomo.
The GDPR and data processing
The analytics software you use will often come down to continue using the solution your organisation has settled on. Google Analytics is the leader in the field and is a very popular go to solution. For those who are paying attention to the GDPR with a view to how their user data is being processed, a solution such as Matomo provides an alternative which is a viable options.
Going to the next level
Analytics solutions will generally work out of teh box for tracking pageviews on the site. Users can be tracked across the site and this information can be correlted against their IP address and geo location. This provides good insight into what is popular, how long users are staying on yoru site and where they are coming from.
However, analytics solutions can be used for much more, including tracking different "dimensions" of data and actions users are taking on your site. Tracking tehse things can open up a new world of insight into how things are changing on your site.
Morpht expertise
Morpht will often implement more advanced tracking solutions so that user actions can be tracked. Javascript on the site can listen out for ceratin actions and then send these to your analytics, further extending the visibility and insights you have.