Cisco Systems is a global manufacturer of network equipment: routers, switches and servers, as well as software for data transmission on the Internet and corporate networks. The company was founded in 1984 in San Jose (California, USA). Today, Cisco dominates the Internet Protocol (IP) -based network equipment segment, and also manufactures cybersecurity, video conferencing systems, and other network equipment and software. In addition, Cisco offers a number of cloud services. Cisco's primary customers are large enterprises and telecommunications service providers, but the company also sells products aimed at small businesses and the public sector. Cisco offers products and services in four categories. The company's infrastructure platforms generate more than half of its revenue. This includes switching devices, routing devices, wireless communications, and data processing solutions. Applications that account for over 10% of revenue are primarily software related to networking and data processing platforms. Applications include collaboration tools (unified communications, Cisco TelePresence video conferencing) as well as AppDynamics and Internet of Things software. The cybersecurity product category generates more than 5% of the company's revenue and includes network security, email security, identity and access, advanced threat protection, and unified exposure management products. In addition, Cisco offers consulting services. Cisco's total revenue in fiscal 2020 was nearly $ 50 billion. The company is expanding its research and development (R&D) investments in areas such as the cloud platform, remote collaboration platform, analytics and telecommunications technologies.

Dell EMC (EMC Corporation until 2016) is an American multinational corporation headquartered in Hopkinton, Massachusetts, United States. Dell EMC sells data storage, information security, virtualization, analytics, cloud computing and other products and services that enable organizations to store, manage, protect, and analyze data. Dell EMC's target markets include large companies and small- and medium-sized businesses across various vertical markets. The company's stock (as EMC Corporation) was added to the New York Stock Exchange on April 6, 1986, and was also listed on the S&P 500 index. Source: https://en.wikipedia.org/wiki/Dell_EMC

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.

Lenovo Group Limited is a Chinese multinational corporation that manufactures personal computers and other electronics. It is one of the world's largest manufacturers of personal computers, smartphones, and servers. Lenovo's headquarters are located in Beijing (PRC), the company is registered in Hong Kong. The main research centers of the company are located in Beijing, Shanghai and Shenzhen (PRC), as well as in Yamato (Japan). The team of the company employs over 52 thousand people, and its clients are located in more than 160 countries In 2005, Lenovo bought out the personal computer division from IBM, and later in 2014 also acquired the IBM server systems business. Also in 2014, Lenovo bought the Motorola Mobility company from Google, but in February 2017 Lenovo announced the termination of the production of smartphones under the Motorola and Vibe trademarks, while continuing to release its mobile products under the Lenovo Moto brand. Today, Lenovo's product portfolio includes tablets, smartphones, laptops, PCs, workstations, servers, storage systems, and other consumer and enterprise-grade electronics. In addition, Lenovo has its own strong R&D department. The company's annual turnover is approaching $ 50 billion.

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.