I have hired a web hosting service from a Finnish provider (Xetnet), with whom I have also registered my domain (dospt.org). This provider offers an optional "external DNS hosting" service for around 20 EUR/year. Quoting from their website:
External DNS Hosting can help speed up your website and improve availability with reduced redundancy.
I have noticed that when first resolving my website's URL, it takes my web browser a few seconds to load it; after that browsing becomes smoother.
I am not familiar with how DNS servers work, and what is the utility of these so-called external DNS hosting versus "internal" DNS hosting. What are pros and cons of these two options? How do they reflect on the user's experience? Is it worth paying the price for the external service?