'Single Page Application (SPA)' refers to a web application or website that enhances user interaction by dynamically updating the current page instead of loading entirely new pages from a server. This method offers a seamless, fluid experience akin to that of a desktop application.

In a SPA, the essential HTML, JavaScript, and CSS codes are either loaded in one go or the required resources are dynamically loaded and appended to the page as needed, typically in reaction to user actions. This approach avoids the necessity of reloading pages or navigating through multiple pages, thereby providing a more streamlined and effective user experience.