Writing under a pen name is usually referred to as "pseudonymity" or "byline". This practice has been used for centuries by authors, poets, and other creative types.
For many of the same reasons that authors today use pen names, many creative people in the past used them too. It allows authors to publish works that might be uncomfortable or controversial to their real name, or to separate their work from their personal lives.
There are some practical benefits to pseudonymity as well. Authoring under a pen name can help an author differentiate himself from other authors and make his work more memorable. Another advantage is that it can help an author protect his personal brand identity.
If you're considering writing under a pen name, here are some things to consider:
• Make sure the pen name doesn't infringe on someone else's rights or trademarks.
• Be consistent in how you display your pen name – across websites, media, etc.
• Be prepared to answer questions about your pen name.
• Be aware that many publishers require authors to complete paperwork before assigning rights to their works.
• Consider the implications of identity theft or false claims that could occur when someone uses your pen name publicly.
• Make sure to use unique identifiers and passcodes to ensure an additional layer of protection for your works and identity.
For more tips and information on publishing under a pen name, check out this article from The Guardian: https://www.theguardian.com/books/2014/dec/02/publishing-under-pen-name-author-tips