Reflected XSS attacks, also known as non-persistent attacks, occur when a malicious script is reflected off a web application to the victim's browser. The script is activated through a link, which sends a request to a website with a vulnerability that enables execution of malicious scripts.
Stored or persistent cross-site scripting (XSS) is a type of XSS where the attacker first sends the payload to the web application, then the application saves the payload (e.g., in a database or server-side text files), and finally, the application unintentionally executes the payload for every victim visiting its web pages.