Liquid computing refers to a style of workflow interaction of applications and computing services across multiple devices, such as computers, smartphones, and tablets. The term was coined in July 2014 by InfoWorld, [1] [2] [3] [4] [5] [6] but the underlying concepts have long existed in computer science, such as in the notions of pervasive computing and ubiquitous computing. The key differentiator for liquid computing over other related notions is that of being focused on the movement among devices of a workflow involving people.
In a liquid computing approach, a person might work on a task on one device, then go to another device that detects the task in progress at the first device and offer to take over that task. For example, you might begin composing an email on a smartphone and when you come near your computer, its mail software detects the in-progress email and lets you continue to work on it on the computer. The data involved, including its current state, flows from one device to another (more accurately, from an application on a device to an application on another device), thus the term "liquid computing." An example of this approach is Apple's Handoff (Continuity) service in iOS 8 and OS X Yosemite (the feature is available only for compatible devices, such as iOS devices with a Lightning port and 2012-or-later Mac models that support Bluetooth Low Energy and Wi-Fi Direct). [7] [8]
Google has announced a similar approach for applications in its Android Lollipop operating system and its ChromeOS operating system to interact with each other in a manner similar to Handoff. [9]
A limitation of current liquid computing implementations is that they are confined to specific vendors' platforms, such as within Apple's iOS and OS X pair or within Google's Android and ChromeOS pair. That means workflows can't flow across different vendors' devices, such as from an Apple iPad to a Microsoft Windows PC. That is not a technical limitation of the liquid computing concept but a vendor decision to encourage adoption of its product ecosystem. Both Apple and Google, for example, make liquid computing capabilities available to developers through a set of APIs that theoretically could be made available to competing platforms, but currently are not. To address this problem, the liquid computing concept can be applied to Web applications running across different Web-enabled devices. [10]
Several operating systems — Apple's iOS and OS X [11] and Microsoft's Windows 8 [12] — can sync settings across multiple devices, as can the Google Chrome browser and Apple Safari browser. The cross-device interaction concept is similar to liquid computing, but lacks the workflow characteristic of liquid computing.
Another related concept involves transferring a service from one device to another, such as sending a phone call or text message from a phone to a computer. Apple does not include this capability (available in OS X Yosemite and iOS 8) in its definition of Handoff, but instead assigns this feature to its set of services called Continuity, [13] which includes Handoff. BlackBerry has a similar capability called Blend available for its smartphones to send calls or texts to OS X Macs and Windows PCs. These transfer services are similar to phone or email forwarding in that the communications is forwarded to another available device (usually via a Wi-Fi connection), and there's no interaction with the data itself as there is in liquid computing. Also, liquid computing allows multiple handoffs during the workflow, whereas communications transfers do not.
Likewise, the Internet of things notion is similar to liquid computing in that it involves direct communication among devices for a computing-oriented purpose, such as analyzing a person's level of physical activity, tracking users in a shopping mall to determine coupon offers, or correlating traffic conditions and flow to recommend alternative routes. Data flows among devices or to a central application hosted on a back-end server, but at most only part of the workflow involves a person, not the entire chain of activity.
The various kinds of computer-to-computer interactions and human-computer interactions that include liquid computing are not exclusive to each other; the various type of interactions can be combined. [14]
The GUI, graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, instead of text-based UIs, typed command labels or text navigation. GUIs were introduced in reaction to the perceived steep learning curve of CLIs, which require commands to be typed on a computer keyboard.
macOS is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and laptop computers it is the second most widely used desktop OS, after Microsoft Windows and ahead of ChromeOS.
A computing platform or digital platform is an environment in which a piece of software is executed. It may be the hardware or the operating system (OS), even a web browser and associated application programming interfaces, or other underlying software, as long as the program code is executed with it. Computing platforms have different abstraction levels, including a computer architecture, an OS, or runtime libraries. A computing platform is the stage on which computer programs can run.
Netbook was a commonly used term that identified a product class of small and inexpensive laptops which were sold from 2007 to around 2013. These machines were designed primarily as cost-effective tools for consumers to access the Internet from any location before the widespread advent of smartphones, and as a result, generally had lower-end hardware specifications than consumer laptops of the time, being primarily intended as clients for Internet services.
A rich web application is a web application that has many of the characteristics of desktop application software. The concept is closely related to a single-page application, and may allow the user interactive features such as drag and drop, background menu, WYSIWYG editing, etc. The concept was first introduced in 2002 by Macromedia to describe Macromedia Flash MX product. Throughout the 2000-s, the term was generalized to describe web applications developed with other competing browser plugin technologies including Java applets, Microsoft Silverlight.
iWork is an office suite of applications created by Apple Inc. for its macOS and iOS operating systems, and also available cross-platform through the iCloud website.
A mobile operating system is an operating system for mobile phones, tablets, smartwatches, smartglasses, 2-in-1 PCs, smart speakers, or other mobile devices. While computers such as typical laptops are 'mobile', the operating systems used on them are generally not considered mobile ones, as they were originally designed for desktop computers that historically did not have or need specific mobile features. This line distinguishing mobile and other forms has become blurred in recent years, this is due to the fact that newer devices have become smaller and more mobile unlike hardware of the past. Key notabilities blurring this line are the introduction of tablet computers and light-weight laptops.
The family of Mac operating systems developed by Apple Inc. includes the graphical user interface-based operating systems it has designed for use with its Mac series of personal computers since 1984, as well as the related system software it once created for compatible third-party systems.
ChromeOS, sometimes stylized as chromeOS and formerly styled as Chrome OS, is a Linux-based operating system designed by Google. It is derived from the open-source ChromiumOS and uses the Google Chrome web browser as its principal user interface.
OS X Lion, also known as Mac OS X Lion, is the eighth major release of macOS, Apple's desktop and server operating system for Mac computers.
AirDrop is a proprietary wireless ad hoc service in Apple Inc.'s iOS and macOS operating systems, introduced in Mac OS X Lion and iOS 7, which can transfer files among supported Macintosh computers and iOS devices by means of close-range wireless communication. This communication takes place over Apple Wireless Direct Link 'Action Frames' and 'Data Frames' using generated link-local IPv6 addresses instead of the Wi-Fi chip's fixed MAC address.
A Chromebook is a laptop or tablet running the Linux-based ChromeOS as its operating system. Initially designed to heavily rely on web applications for tasks using the Google Chrome browser, Chromebooks have since expanded to be able to run Android and full-fledged Linux apps since 2017 and 2018, respectively. All supported apps can be installed and launched alongside each other.
iCloud is a cloud service from Apple Inc. launched on October 12, 2011 as a successor to MobileMe. As of 2018, the service had an estimated 850 million users, up from 782 million users in 2016.
The Post-PC era is a market trend observed during the late 2000s and early 2010s involving a decline in the sales of personal computers (PCs) in favor of post-PC devices; which include mobile devices such as smartphones and tablet computers as well as other mobile computers such as wearable and ubiquitous ones. These devices emphasize portability and connectivity, including the use of cloud-based services, more focused "apps" to perform tasks, and the ability to synchronize information between multiple devices seamlessly.
OS X Yosemite is the eleventh major release of macOS, Apple Inc.'s desktop and server operating system for Macintosh computers.
OS X El Capitan is the twelfth major release of macOS, Apple Inc.'s desktop and server operating system for Macintosh. It focuses mainly on performance, stability, and security. Following the California location-based naming scheme introduced with OS X Mavericks, El Capitan was named after a rock formation in Yosemite National Park. El Capitan is the final version to be released under the name OS X. OS X El Capitan received far better reviews than did Yosemite.
A progressive web application (PWA), commonly known as a progressive web app, is a type of application software delivered through the web, built using common web technologies including HTML, CSS, JavaScript, and WebAssembly. It is intended to work on any platform with a standards-compliant browser, including desktop and mobile devices.
Comparison of user features of operating systems refers to a comparison of the general user features of major operating systems in a narrative format. It does not encompass a full exhaustive comparison or description of all technical details of all operating systems. It is a comparison of basic roles and the most prominent features. It also includes the most important features of the operating system's origins, historical development, and role.