There's a lot of confusion surrounding the differences between UX writing and related disciplines such as copywriting, content design, and content strategy. Here’s what UX writing is not:

• Copywriting is the most different from UX writing than other disciplines. Unlike UX writing, copywriting focuses on creating engaging content, not guiding users through it. In short, copywriting is related to marketing, not user experience.
• Content design is more about the product's design process, while UX writing is about the words users read or hear when they're using a product — in theory. In practice, many job listings use these terms interchangeably.
• Content strategy looks at a long-term strategy that uses content to achieve a particular vision. It differs from UX writing which mostly focuses on the words in a product. In practice, a content strategist and a UX writer can be the same person within an organization due to the overlap of job functions.