SharePoint supports intranet, extranet and internet applications from a single integrated platform.
On-premises deployments of SharePoint 2019 require SharePoint Server 2019 for each running instance of the software and CALs are required for each person or device accessing a SharePoint Server.
SharePoint Standard 2019
Utilise a single infrastructure for all your business websites, build communities with an integrated collaboration platform, access a limited set of features for Enterprise Content Management as well as a limited search function.
SharePoint Enterprise 2019
In addition to everything in the Standard edition, get full access to Enterprise Content Management features and a powerful search function across people, video, and content. Also benefit from Access Services and InfoPath Services, as well as business intelligence tools like PowerView, PerformancePoint Services and Visio Services.