Writing (as a verb) is the art of creating text in written form (as opposed to verbal form, as in speaking). The text can be anything from a fictional story to a personal letter, from a dishwasher user manual to a historic novel, from a news report to a poem.
Writing (as a noun) is the product of such work. A person who writes is an author.
Writing actually describes three separate skills: First, the mechanical skill to inscribe characters on a medium; second, the knowledge and application of correct grammar and spelling rules of the language one is writing in; third, the creative art of putting events, facts, thoughts and feelings in words, creating a text that serves its purpose - whatever it may be - well.
Media and publishing
The traditional medium for writing is paper - e.g. with a pen, pencil, or a typewriter. Today, much writing is done in digital form on a computer. For example, the digital pendant to a traditional letter is an e-mail.
Writing can be published, i.e. made available for reading to a big audience. Traditional publishing media are books, magazines, newspapers, and so on. Digital methods of publishing usually depend on the Internet and include newsgroups, web groups, forums, websites, blogs, e-books, webzines, and many more.
Writing on spanking
As the art of writing is able to convey events, facts, thoughts and feelings, it is well-suited to approach the subject of spanking in many different ways. Authors can write about spanking e.g. in the form of spanking stories or spanking novels. Most of this genre is fiction. Authors can also write factual information about spanking (e.g. here in this wiki, or in their own websites, such as World Corporal Punishment Research), or write articles for spanking magazines, or write postings in spanking newsgroups, spanking web forums and groups, or in their own spanking blogs.
Very few people write spanking-related text for money. Like most artists who draw spanking art, most authors in this genre are non-professionals who enjoy writing on spanking as a hobby.