Also trying to add the ability to detect a video and download it to the application in short a web-based app used for download any kind of video and has the ability to store
URL :
URL is a swift struct, so is passed by value.
NSURL :
NSURL is an Objective-C class. Is inherits from NSObject
URL; use NSURL when you need reference semantics or other Foundation-specific behavior.Both URL and NSURL is accepted in swift. but you have used swift then most refer URL MORE.