For future reference, the extra stuff is everything after the question mark. It’s not always bad stuff; the question mark is for a bunch of queries, including links to specific time stamps on YouTube videos. Adding ?t=42 to the end of a clean YouTube link will start the video at 42 seconds as an example: https://youtu.be/dQw4w9WgXcQ?t=42
Although these “query strings” are sometimes useful, most of the time, they’re just for tracking purposes and can be removed with no issue. “If you don’t know what it does, it’s probably not needed” is a good rule of thumb
For future reference, the extra stuff is everything after the question mark. It’s not always bad stuff; the question mark is for a bunch of queries, including links to specific time stamps on YouTube videos. Adding ?t=42 to the end of a clean YouTube link will start the video at 42 seconds as an example: https://youtu.be/dQw4w9WgXcQ?t=42
Although these “query strings” are sometimes useful, most of the time, they’re just for tracking purposes and can be removed with no issue. “If you don’t know what it does, it’s probably not needed” is a good rule of thumb