Static web apps that require only a single load in a web browser are referred to as Single page web apps.
Backend data is accessed via GraphQL or REST APIs that fetch content from a data store and update the UI without requiring a page reload.
This kind of application follows generally the progressive enhancement concept where the idea is to start small and then progressively adds up functionality. Therefore, they are also generally known as progressive web applications.
Hypertext based (Progressive)
HyperText Progressive app are based on the swap of HTML fragment. See What are Hypertext Progressive based App ?