Usage share of operating systems Usage share of operating systems The usage share of operating systems is the percentage of computing devices that run each operating system at any particular time. All such figures are necessarily estimates because data about operating system share is difficult to obtain; there are few reliable primary sources—and no agreed methodologies for its collection. In the personal computing platform area of smartphones and watches two systems dominate: Google's Android with over 2.7 billion users and Apple's iOS and macOS combined with over 1.3 billion users. In the area of desktop and laptop computers, Microsoft Windows is generally above 75% in
Distributed operating system and functionality required of an OS but adds attributes and particular configurations to allow it to support additional requirements such as increased scale and availability. To a user, a distributed OS works in a manner similar to a single-node, monolithic operating system. That is, although it consists of multiple nodes, it appears to users and applications as a single-node. Separating minimal system-level functionality from additional user-level modular services provides a “separation of mechanism and policy.” Mechanism and policy can be simply interpreted as "what something is done" versus "how something is done," respectively. This separation increases flexibility and scalability. At