Recently I've had a couple of people ask me what technical writers do. Technical writing is one of the lesser-known jobs that can be found orbiting the software engineering solar system.
To explain to you in plain terms I will have to give you some fun facts; Microsoft Word is a 38 years old tool released in 1983, the oldest computer program still in use today is the MOCAS (Mechanization of Contract Administration Services), used by the United States Department of Defense, the software is 63 years old.
SOFTWARE CAN OUTLIVE THEIR CREATOR(S) BECAUSE OF TECHNICAL WRITERS
Writing code isn't really easy as you can probably guess by now, the one thing all software engineers agree on is that reading code that is written by someone else is way harder than writing code. Technical writers are the reason why software can outlive their creator(s).
Most of the people who wrote the software above are either dead or very retired, the people managing and extending the software today were mostly not born when the software above were launched.
TECHNICAL WRITERS ARE THE CUSTODIAN OF THE PROCESSES AND EVOLUTION OF SOFTWARE SOLUTIONS
Technical writers are like historians/librarians, they are custodians of information and they help document esoteric terms, code, APIs (Application Programming Interface), and the evolution of software solutions.
Because of the work of technical writers, it's easier to learn a new programming language (from the documentation), it is easier to pick up a software solution you didn't write and extend it, it is also possible to educate the general public about how to use a software solution or product.
This line of work does require an understanding of programming, which is what puts the "technical" in the job title. Technical writers are just like normal writers, only we're less mainstream, we write about cool stuff most people don't (and can't) understand without a little assistance.