What is the difference between a single-page application (SPA) and a traditional website?

In SPA, content loading and transitions between "pages" occur dynamically, without a full page reload. On a classic website, each transition to a new page requires reloading the entire HTML document.

SPA:

• Pros:
  • Fast response to user actions (less noticeable delays during navigation).
  • Better UX (feeling of a native app).
  • Less traffic between client and server (only necessary data is loaded).
• Cons:
  • SEO difficulties (search engines may find it harder to index dynamic content).
  • Higher initial load time (loading all necessary resources at once).
  • May require more browser resources on the client.
  • More complex development and debugging.

Classic website:

• Pros:
  • Good search engine indexing (SEO).
  • Simpler development for less interactive sites.
  • Better performance on resource-limited devices.
• Cons:
  • Slow navigation (full page reload on each transition).
  • Worse UX (perceived "lag" during transitions).
  • More traffic due to constant reloading of all content.

Comparison table:

Characteristic	SPA	Classic website
Page load	Dynamic (partial update)	Full reload
Transitions	Fast, without reload	Slow, with full reload
Traffic	Less (loading data)	More (loading HTML, CSS, JS, data)
SEO	Difficult (requires SSR/pre-rendering)	Good
UX	Better, feels like native	Worse, noticeable delays
Initial Load Time	Higher	Lower (for simple pages)
Development complexity	Higher	Lower