Technical writers write user's manuals and technical documentation for a wide variety of products. The writer must understand how to describe things for other people in writing so that they can understand it. This requires a highly logical thinking process, and excellent language skills. Most technical writing positions require a degree.
Many technical writers pursue degree programs with a highly technical bent. This helps them develop a better understanding of the topic matter which they are writing about. A technical background also helps them relate better to the developers of the product, and to do a more complete job of understanding the key points about a particular product.