A technology company (or tech company) is an electronics-based technology company, including, for example, business relating to digital electronics, software, and internet-related services, such as e-commerce services. Details According to Fortune, as of 2020, the ten largest technology companies by revenue are: Apple Inc., Samsung, Foxconn, Alphabet Inc., Microsoft, Huawei, Dell Technologies, Hitachi, IBM, and Sony. Amazon has higher revenue than Apple, but is classified by Fortune in the retail sector. The most profitable listed in 2020 are Apple Inc., Microsoft, Alphabet Inc., Intel, Facebook, Samsung, and Tencent. Apple Inc., Alphabet Inc., Facebook, Microsoft, and Amazon. com, Inc. are often referred to as the Big Five multinational technology companies based in the United States. These five technology companies dominate major functions, e-commerce channels, and information of the entire Internet ecosystem. As of 2017, the Bigs Five had a combined valuation of over $3. 3 trillion and make up more than 40 percent of the value of the Nasdaq 100 index. Many large tech companies have a reputation for innovation, spending large sums of money annually on research and development. According to PwC's 2017 Global Innovation 1000 ranking, tech companies made up nine of the 20 most innovative companies in the world, with the top R&D spender (as measured by expenditure) being Amazon, followed by Alphabet Inc., and then Intel. As a result of numerous influential tech companies and tech startups opening offices in proximity to one another, a number of technology districts have developed in various areas across the globe. These include: Silicon Valley in the San Francisco Bay Area, Silicon Wadi in Israel, Silicon Docks in Dublin, Silicon Hills in Austin, Tech City in London, Digital Media City in Seoul, Zhongguancun in Beijing, and International Tech Park in Bangalore. Information-technology (IT) companies and high-tech companies comprise subsets of the set of technology companies.