The United States Patent and Trademark Office defines copyright as an intellectual property protection for “original...
The United States Patent and Trademark Office defines copyright as an intellectual property protection for “original works of authorship including literary, dramatic, musical and artistic works, such as poetry, novels, movies, songs, computer software and architecture.”
So, if you were to write a book, draw a picture, perform a song, build code, etc. you can apply for copyright protection for your work. This can help protect against copying, distributing, changing, marketing or otherwise using your creative work without your permission.
It's important to note that a copyright is different from a trademark. For a good explanation on the distinction between the two, read this: What's the Difference Between a Trademark and a Copyright?