Digital Realty Trust, Inc. through its controlling interest in Digital Realty Trust, L.P. (the Operating Partnership) and the subsidiaries of the Operating Partnership (collectively, we, our, us or the Company) is a leading global provider of data center, colocation and interconnection solutions for customers across a variety of industry verticals ranging from cloud and information technology services, communications and social networking to financial services, manufacturing, energy, healthcare, and consumer products. The Operating Partnership, a Maryland limited partnership, is the entity through which Digital Realty Trust, Inc., a Maryland corporation, conducts its business of owning, acquiring, developing and operating data centers. Digital Realty Trust, Inc. operates as a REIT for federal income tax purposes. A summary of our data center portfolio as of June 30, 2018 and December 31, 2017 is as follows:



	Data Centers
	As of June 30, 2018				As of December 31, 2017
Region	Operating	Held for Sale	Unconsolidated Joint Ventures	Total	Operating	Held for Sale	Unconsolidated Joint Ventures	Total
United States	132	—	14	146	131	7	14	152
Europe	37	—	—	37	38	—	—	38
Asia	3	—	4	7	3	—	4	7
Australia	5	—	—	5	5	—	—	5
Canada	3	—	—	3	3	—	—	3
Total	180	—	18	198	180	7	18	205

We are diversified in major metropolitan areas where data center and technology customers are concentrated, including the Atlanta, Boston, Chicago, Dallas, Los Angeles, New York, Northern Virginia, Phoenix, San Francisco, Seattle, Silicon Valley and Toronto metropolitan areas in North America, the Amsterdam, Dublin, Frankfurt, London and Paris metropolitan areas in Europe and the Hong Kong, Melbourne, Osaka, Singapore, Sydney, and Tokyo metropolitan areas in the Asia Pacific region. The portfolio consists of data centers, Internet gateway facilities and office and other non-data center space.

The Operating Partnership was formed on July 21, 2004 in anticipation of Digital Realty Trust, Inc.’s initial public offering (IPO) on November 3, 2004 and commenced operations on that date. As of June 30, 2018, Digital Realty Trust, Inc. owns a 96.0% common interest and a 100.0% preferred interest in the Operating Partnership. As of December 31, 2017, Digital Realty Trust, Inc. owned a 96.0% common interest and a 100.0% preferred interest in the Operating Partnership. As sole general partner of the Operating Partnership, Digital Realty Trust, Inc. has the full, exclusive and complete responsibility for the Operating Partnership’s day-to-day management and control. The limited partners of the Operating Partnership do not have rights to replace Digital Realty Trust, Inc. as the general partner nor do they have participating rights, although they do have certain protective rights.