Technical communicators are called technical writers by most in industry. We are part of a broad spectrum of communications professionals who research and gather information and present it in a useable form for the audience.
There is considerable overlap between the skill set of technical communicators and the other communications professions such as business writing, Plain English writing, media and communications, and journalism. Some technical communicators spend their whole career at the very technical end of the spectrum, while others use their skills to write less technical material such as business documents (policies, procedures, reports) and a few even stray into the media and communications space, writing marketing materials and web content.
What all communication professionals have in common is that they provide their audience with relevant information, presented so that they can find what they need and understand it on first reading.