Islands of Interactivity, just means you control when your components load. The idea being you load the page faster and improve user experience. You can set a comment form at the bottom of the page only to load when it becomes visible. You might set a chatbot to load only once the main thread has become idle. Of course, you can still set key components to load straight away. In fact, using an islands architecture means the key components can load faster. All these possibilities and more are available with Astro.