To switch to each mode, easily change value of <WebAppDeploymentType> in the src/Directory.build.props file in Solution Items root folder.

It's referring to a Typical Single Page Application (SPA) without pre-rendering.

Note: We'd recommend using next options for production and use Spa only for development / debugging.

Server-side rendering (SSR), is the ability of an application to contribute by displaying the web-page on the server instead of rendering it in the browser. Server-side sends a fully rendered page to the client; Blazor pre-renders page and sends it as a static page, then later the page becomes an interactive Blazor app. This behavior is intended to serve pages quickly to search engines with time-based positioning. Statically prerender the component along with a marker to indicate the component should later be rendered interactively by the Blazor app. It improve SEO.
It's referring to a Typical Spa with pre-rendering.

Demo: bitplatform.dev

A Blazor WebAssembly app built as a Progressive Web App (PWA) uses modern browser APIs to enable many of the capabilities of a native client app, such as working offline, running in its own app window, launching from the host's operating system, receiving push notifications, and automatically updating in the background.

Demo: adminpanel.bitplatform.dev

Server-side rendering (SSR), is the ability of an application to contribute by displaying the web-page on the server instead of rendering it in the browser. Server-side sends a fully rendered page to the client; Blazor pre-renders page and sends it as a static page, then later the page becomes an interactive Blazor app. This behavior is intended to serve pages quickly to search engines with time-based positioning. Statically prerender the component along with a marker to indicate the component should later be rendered interactively by the Blazor app. It improve SEO.
It's referring to a Typical Pwa with pre-rendering.

Demo: todo.bitplatform.dev

Statically renders the component with the specified parameters. It's recommended when the target is building a static page like a landing page.