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A thin client (sometimes also called a lean, zero or slim client) is a computer or a computer program that depends heavily on another computer (its ''server'') to fulfill its computational roles. This is different from the traditional fat client, which is a computer designed to take on these roles by itself. The specific roles assumed by the server may vary, from providing data persistence (for example, for diskless nodes) to actual information processing on the client’s behalf. Thin clients occur as components of a broader computer infrastructure, where many clients share their computations with the same server. As such, thin client infrastructures can be viewed as providing some computing service via several user interfaces. This is desirable in contexts where individual fat clients have much more functionality or power than the infrastructure requires. Thin-client computing is also a way of easily maintaining computational services at a reduced total cost of ownership.〔 〕 The most common type of modern thin client is a low-end computer terminal which only provides a graphical user interface – or more recently, in some cases, a web browser – to the end user. ==History== Thin clients have their roots in multi-user systems, traditionally mainframes accessed by some sort of terminal computer. As computer graphics matured, these terminals transitioned from providing a command-line interface to a full graphical user interface, as is common on modern advanced thin clients. The prototypical multiuser environment along these lines, Unix, began to support fully graphical X terminals, i.e., devices running display server software, from about 1984. X terminals remained relatively popular even after the arrival of other thin clients in the mid-late 1990s. Modern Unix derivatives like BSD and GNU/Linux continue the tradition of the multi-user, remote display/input session. Typically, X software is not made available on non-X-based thin clients, although no technical reason for this exclusion would prevent it. Windows NT became capable of multi-user operations primarily through the efforts of Citrix Systems, which repackaged NT 3.5.1 as the multi-user operating system WinFrame in 1995. Microsoft licensed this technology back from Citrix and implemented it into Windows NT 4.0 Terminal Server Edition, under a project codenamed ‘Hydra’. Windows NT then became the basis of Windows 2000 and Windows XP. Microsoft Windows systems support graphical terminals via the Remote Desktop Services component. The term ''thin client'' was coined in 1993 by Tim Negris, VP of Server Marketing at Oracle Corp., while working with company founder Larry Ellison on the launch of Oracle 7. At the time, Oracle wished to differentiate their server oriented software from Microsoft’s desktop oriented products. Ellison subsequently popularized Negris’ buzzword with frequent use in his speeches and interviews about Oracle products. The term stuck for several reasons. The earlier term ‘graphical terminal’ had been chosen to distinguish such terminals from text-based terminals, and thus put the emphasis heavily on ''graphics - ''which became obsolete as a distinguishing characteristic in the 1990s as text-only physical terminals themselves became obsolete, and text-only computer systems (a few of which existed in the 1980s) were no longer manufactured. The term ‘thin client’ also conveys better what was then viewed as the fundamental difference: thin clients can be designed with less expensive hardware, because they have reduced computational workloads. By the 2010s, however, thin clients were not the only desktop devices for general purpose computing that were ‘thin’ - in the sense of having a small form factor and being relatively inexpensive. The Nettop form factor for desktop PCs was introduced, and nettops could run full feature Windows or Linux; tablets and tablet-laptop hybrids had also entered the market. However, while there was now little size difference, thin clients retained some key advantages over these competitors, such as not needing a local drive. However, ‘thin client’ can be a misnomer for slim form factor computers using flash memory such as compactflash, SD card, or permanent flash memory as a hard disk substitute. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「thin client」の詳細全文を読む スポンサード リンク
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