There are a number of books, programs, and classes out there today offering to teach "technical writing." Some of these are excellent; prepared by industry veterans who know what they're doing. But some others are basically rehashing old "business writing" concepts and techniques under the guise of "technical writing."
"So what?" you may ask, which is a fair question. And here is the answer: if you are seriously considering to go out there and find yourself a job as a "technical writer" then you need to have at least one technical document prepared according to industry standards and expectations. Business writing in general will of course help you communicate better and conduct your business more efficiently. That's why it's a good thing. But when it comes to finding a technical writing job, business writing won't help you much. No recruiter will accept a business writing sample as a proof of your technical writing skills, especially in the hi-tech sector where I've been working for over 10 years now.
Business writing is all kinds of copy generated to administer, communicate with and control others in a work environment. It covers all office communications, and topics like how to write a memo; how to write an e-mail; how to prepare a report; how to write meeting minutes; all kinds of business letters, etc.
While helpful, such knowledge will not be enough to find a job in the highly competitive field of modern technical communications. Instead, what you need to learn is the kind of documentation generated every day in such hi-tech industries as software, hardware, networking, telecommunications, manufacturing, chemicals, finance, defense, etc.
Does your instructor help you learn what a "scope" document is, for example, and how it is written? How do you prepare and write "release notes"? What's the crucial difference between an "interface guide" and a "procedural guide"? Do you know how to write a QCP for a defense contractor?
There are many other similar topics that a beginner needs to learn to prepare him or herself for a great career in technical writing. Once you know the crucial difference between "business writing" and "technical writing," you can make a better decision as to which questions to ask before buying a technical writing book or registering in a technical writing program. That way you won't waste your time, money and energy on a product or a program that won't help you reach your main goal. As always the case, knowledge is power in this particular issue as well.