Singer Dhananjay Bedardi on Instagram: "The “#” symbol is known by different names, including number sign, hash, and pound sign, and has several uses, most commonly to indicate a number (e.g., #1) or to create a hashtag on social media for categorizing content. Historically, it was used as an abbreviation for “pound” and in some programming languages, it serves other functions, such as indicating a comment. This video explains how to type the number sign on a keyboard:"