IBM (International Business Machines) ia an american electronic corporation, one of the world's largest manufacturers of all types of computers and software, one of the largest providers of global information networks. The corporation ranks sixth in the list of the largest companies in the world. Headquartered in Armonk, New York, USA. The story begins in the 19th century. IBM manufactures and sells hardware and software, services (hosting, consulting) in the areas from mainframes to nanotechnology.

Microsoft Corporation is an multinational technology company headquartered in Redmond, Washington, that develops, manufactures, licenses, supports and sells computer software, consumer electronics and personal computers and services. Its best known software products are the Microsoft Windows line of operating systems, Microsoft Office office suite, and Internet Explorer and Edge web browsers. Its flagship hardware products are the Xbox video game consoles and the Microsoft Surface tablet lineup. As of 2011, it was the world's largest software maker by revenue, and one of the world's most valuable companies.

Oracle Corporation is an american multinational computer technology corporation headquartered in Redwood Shores, California. The company specializes primarily in developing and marketing database software and technology, cloud engineered systems, and enterprise software products — particularly its own brands of database management systems. In 2018, Oracle was the third-largest software maker by revenue, after Microsoft and Alphabet. The company also develops and builds tools for database development and systems of middle-tier software, enterprise resource planning (ERP) software, customer relationship management (CRM) software, and supply chain management (SCM) software. Source: https://en.wikipedia.org/wiki/Oracle_Corporation