Copyrights are typically thought of as creative works of authorship. There is a very low bar for creativity, which means that even minimally creative works qualify for copyright, such as children’s drawings (read: scribbles). Common examples of works that are copyrighted are literary works, pictures, musical works, computer code, and websites.
Compared to trademarks, the cost to register a copyright is minimal. The reason for this is that when you apply for a copyright registration, no one scrutinizes your application to determine whether you should be allowed one. Instead, the process is more ministerial or administrative, if you pay a fee and fill out a form, you will most likely get your registration.
A copyright registration is a prerequisite to a lawsuit. In other words, unlike trademarks, you need to register your work before you can sue someone. Also, copyrights are litigated entirely in federal courts.