The proper definition of what industry a particular company belongs is the definition of that industry itself
OK, let's do that. Here's a definition from a business dictionary:
http://www.businessdictionary.com/definition/technology.html
The purposeful application of information in the design, production, and utilization of goods and services, and in the organization of human activities.
From inc.com:
What's the definition of a tech company? It's complicated
"You are a technology company if you are in the business of selling technology--if you make money by selling applied scientific knowledge that solves a concrete problem."
-- Alex Payne, Co-Founder, Simple
"It's generally a company whose primary business is selling tech or tech services. A more nuanced definition is a company with tech or tech services as a key part of its business. It's a hard question."
-- Todd Berkowitz, VP of Research, Gartner
"A tech company uses technology to create an unfair advantage in terms of product uniqueness or scale or improved margins. Ask the question: Could this company exist without technology? If the answer is no, it has to be a tech company."
-- Greg Bettinelli, Partner, Upfront Ventures
"I think there's a false dichotomy in the idea that a company either is or is not a tech company. I think it's possible for a company to be a hybrid if tech is giving it an edge over incumbents."
-- Hayley Barna, Venture Partner, First Round Capital