If you don’t supply it, WordPress uses the global value for that variable. For get_the_title() there is only one parameter, $post, which is optional. These are the pieces of information you can pass along with it to get the response you want. Next, the parameters for the function are listed. In this case, it lets us know the title of a post is retrieved, and that there are certain conditions where the word “Protected” or “Private” appears before the title. First, there is a description of what the function does.