Thin Clients

Thin Clients
A thin client, sometimes also called a lean or slim client is a clients computer or client software in client server architecture networks which depends primarily on the central server for processing activities, and mainly focuses on conveying input and output between the user and the remote server. In contrast, a thick or fat clients does as much processing as possible and passes only data for communication and storage to the server.
Introduction :
The thin client is a PC with less of everything. In designing a computer system, there are decisions to be made about processing, storage, software and user interface. With the reality of reliable high-speed networking, it is possible to change the location of any of these with respect to the others. A gigabit/s network is faster than a PCI bus and many hard drives, so each function can be in a different location. Choices will be made depending on the total cost, cost of operation, reliability, performance and usability of the system. The thin client is closely connected to the user interface.
In a thin client/server system, the only software that is installed on the thin client is the user interface, certain frequently used applications, and a networked operating system. This software can be loaded from a local drive, the server at boot, or as needed. By simplifying the load on the thin client, it can be a very small, low-powered device giving lower costs to purchase and to operate per seat. The server, or a cluster of servers has the full weight of all the applications, services, and data. By keeping a few servers busy and many thin clients lightly loaded, users can expect easier system management and lower costs, as well as all the advantages of networked computing: central storage/backup and easier security

History :
What are now called thin clients were originally called "graphical terminals" when they first appeared, because they were a natural development of the text terminal that had gone before them. Text terminals are essentially a thin client for computers that use text for input and output with humans, but are generally not classified as such because they come from an earlier computing era. Today's thin clients must give the user the experience of running the graphical, high-computation programs that are in use today.

It is said that the term "thin client" started to be used instead of "graphical terminal" for the following reasons:

1) When thin clients started to come back into vogue,fat clients had long been the norm in most environments. Many IT workers and managers used to working with fat clients such as PCs and Macs would have been unfamiliar with the term "graphical terminal".
2) As a marketing term, it sounds short and snappy – and also, importantly, it made the technology sound innovative and technologically advanced, even though it was neither – X terminals had been acting as thin clients years before the term was widely used in the IT industry.
3) "Thin Client" also reflects the fact that most of these devices leave out much of the hardware found in typical PCs, such as hard drive, cooling fan and much of the RAM.


Definitions
A thin client is a network computer without a user writable long term storage device, which, in client/server applications, is designed to be especially small so that the bulk of the data processing occurs on the server. The embedded OS in a thin client is stored in a "flash drive", in a Disk on Module(DOM), or is downloaded over the network at boot-up. The embedded OS in a thin client usually uses some kind of write filter so that the OS and its configuration can only be changed by administrators.


Industrial thin client applications
Since 2006 there has been a growing interest in using Thin Client technology in hazardous areas, such as oil & gas exploration, military mobile use to monitor gen sets and mobile missile installations, and in industry in Zone 1 areas where hardened industrial computers can be prohibitively expensive. Thin Client hardware is easier to seal against environmental hazards and contamination, and can sometimes withstand a wider temperature and vibration level, due to simplified components and lack of moving parts, such as hard drives and cooling fans.
breaches, lesser weight and greater mobility, and lower incidence of OS failures. Some Thin Client solutions (such as ACP's ThinManager Ready Thin Clients) are tightly coupled with specialized management software that enhances the basic features offered by server operating systems.
Thin Client products enable easy-to-employ industry standard network creation and control at hazardous area zones for less cost and with less risk of failure than full computer systems. In fact, in the first quarter of 2007, mandates have been created by the US Armed Forces to look at Thin Client solutions in all field applications. The military is primarily interested in Thin Client technology in the field due to its improved cost control, more robust construction, less vulnerability to failure and security.

Advantages of thin clients

1) Lower IT administration costs. Thin clients are managed almost entirely at the server. The hardware has fewer points of failure and the client is simpler (and often lacks permanent storage), providing protection from malware.
2) Easier to secure. Thin clients can be designed so that no application data ever resides on the client (just whatever is displayed), centralizing malware protection and reducing the risks of physical data theft.
3) Enhanced data security. If a thin-client device suffer serious mishap or industrial accident, no data will be lost, as it resides on the terminal server and not the point-of-operation device.
4) Lower hardware costs. Thin client hardware is generally cheaper because it does not contain a disk, application memory, or a powerful processor. They also generally have a longer period before requiring an upgrade or becoming obsolete.
5) Less energy consumption. Dedicated thin client hardware has much lower energy consumption than typical thick client PCs. This not only reduces energy costs but may mean that in some cases air-conditioning systems are not required or need not be upgraded which can be a significant cost saving and contribute to achieving energy saving targets. However, more powerful servers and communications are required.
6) Easier hardware failure management. If a thin client fails, replacement can simply be swapped in while the client is repaired; the user is not inconvenienced because their data is not on the client
7) Operable in Hostile Environments. Most thin clients have no moving parts so can be used in dusty environments without the worry of PC fans clogging up and overheating and burning out the PC.
8)Lower noise. The aforementioned removal of fans reduces the noise produced by the unit. This can create a more pleasant and productive working environment.
9) Less wasted hardware. Computer hardware contains heavy metals and plastics and requires energy and resources to create. Thin clients can remain in service longer and ultimately produce less surplus computer hardware than an equivalent thick client installation because they can be made with no moving parts.
10) More efficient use of computing resources. A typical thick-client will be specified to cope with the maximum load the user needs, which can be inefficient at times when it is not used. In contrast, thin clients only use the exact amount of computing resources required by the current task – in a large network, there is a high probability the load from each user will fluctuate in a different cycle to that of another use.
Device for running a thin client application program

"Thin client" has also been used as a marketing term for computer appliances designed to run thin client software. The SMARTSTATION THIN CLIENT, NEC US110, IGEL Technology Universal Desktops, Wyse Winterms, Neoware's acquired by Hewlett-Packard HP Compaq t-series, Chip PC Jack PC and Xtreme PC Series, SaaS style Nexterm NEXterminal, Sabertooth TC , TC3ProjectACP's ThinManager Ready Thin Clients, X terminal, ClearCube, Koolu, LISCON TCs, ThinCan or web kiosk might be considered thin clients in this sense.