Answer:
C Sharp, or C#, is a very popular coding language, is one that is used for web applications, game development, a lot of Microsoft applications, and a lot more. Even unity uses it! It can be difficult to learn at times (Speaking from experience), but the payoff is great!
Some things you’ll be able to do with C# is; some high end game development (Personally, I just use lua, as it’s easier to use, faster, and just works better for me), some more interactive things for websites (It for me seems to have more options for making interactive types of stuff on websites, and other types of applications), and some other things capable of almost all coding languages.
Some languages that are similar are Java, C+, C++, and at certain (sometimes remote), times, lua. I said this because if you know them, you’ll be able to learn C sharp easier.
Hope This Helped!