Utility computingUtility computing, or computer utility, is a service provisioning model in which a service provider makes computing resources and infrastructure management available to the customer as needed, and charges them for specific usage rather than a flat rate. Like other types of on-demand computing (such as grid computing), the utility model seeks to maximize the efficient use of resources and/or minimize associated costs. Utility is the packaging of system resources, such as computation, storage and services, as a metered service.
Energy conversion efficiencyEnergy conversion efficiency (η) is the ratio between the useful output of an energy conversion machine and the input, in energy terms. The input, as well as the useful output may be chemical, electric power, mechanical work, light (radiation), or heat. The resulting value, η (eta), ranges between 0 and 1. Energy conversion efficiency depends on the usefulness of the output. All or part of the heat produced from burning a fuel may become rejected waste heat if, for example, work is the desired output from a thermodynamic cycle.
Copland (operating system)Copland is an operating system developed by Apple for Macintosh computers between 1994 and 1996 but never commercially released. It was intended to be released as System 8, and later, Mac OS 8. Planned as a modern successor to the aging System 7, Copland introduced protected memory, preemptive multitasking, and several new underlying operating system features, while retaining compatibility with existing Mac applications. Copland's tentatively planned successor, codenamed Gershwin, was intended to add more advanced features such as application-level multithreading.
Platform as a servicePlatform as a service (PaaS) or application platform as a service (aPaaS) or platform-based service is a category of cloud computing services that allows customers to provision, instantiate, run, and manage a modular bundle comprising a computing platform and one or more applications, without the complexity of building and maintaining the infrastructure typically associated with developing and launching the application(s), and to allow developers to create, develop, and package such software bundles.
Aqua (user interface)Aqua is the graphical user interface, design language and visual theme of Apple's macOS operating system. It was originally based on the theme of water, with droplet-like components and a liberal use of reflection effects and translucency. Its goal is to "incorporate color, depth, translucence, and complex textures into a visually appealing interface" in macOS applications. At its introduction, Steve Jobs noted that "... it's liquid, one of the design goals was when you saw it you wanted to lick it".
System administratorA system administrator, sysadmin, or admin is a person who is responsible for the upkeep, configuration, and reliable operation of computer systems, especially multi-user computers, such as servers. The system administrator seeks to ensure that the uptime, performance, resources, and security of the computers they manage meet the needs of the users, without exceeding a set budget when doing so.
