In this video we're going to examine the different types of computers we can find today.

Transcription

1 In this video we're going to examine the different types of computers we can find today.

2 In reverse order by their calculus power, the faster and more powerful ones are supercomputers. They are designed for complex, high-demanding calculus tasks, including weather forecasting, physical simulations and cryptoanalysis, among others. They are usually very expensive and their performance is measured in FLOPS (floating point operations per second)

3 Mainframes are used by large organisations. They're not as specific as supercomputers. They are related with massive data applications, involving bulk data processing as the census, industry and consumer statistics, enterprise resource planning, transaction processing and, more recently, big data analysis. Insurance companies, banks, public administrations and research centres are the typical users. Modern mainframes can run multiple different instances of different operating systems at the same time. This technique of virtual machines allows applications to run as if they were on physically separated computers. While mainframes pioneered this capability, virtualisation is now available on most families of computer systems, though not always to the same degree or level of sophistication. Mainframes can add hot swap system capacity without disrupting system function. They can do so with a specificity

4 and granularity not usually available in most server solutions.

5 Servers are similar to mainframes, they act as centralised resource providers with higher capacity than desktop computers. The main difference between them is that mainframes are oriented to running specific corporate applications and servers are focused on sharing resources (mainly storage, but also Internet access, computing power or databases) for users. The range of prices and computing capacities is broader in servers than in mainframes, as you can find small servers with capacities and prices not much higher than those of high end workstations. Mainframes are always powerful

6 and expensive computers. Nowadays most Internet services are provided by servers (web pages, ,...)

7 Both mainframes and servers are multiuser machines. That means that they attend simultaneously several users, typically much more than the number of processors they have. To do that, they use a technique called time sharing. Basically, time sharing consist on assigning the resources of the machine to one user during a very short period of time. The computer changes quickly among the active users and, as a result, they give the sensation that the computer is only dedicated to each one of them. This is also called multitasking. Most of them have several processors working at the same time and accessing to shared memory and devices, what is called multiprocessing. These processors can be assigned to solve different parts of the same task, in what is called parallel processing.

8 In the particular case that a computer executes multiple concurrent processes in different processors it can be also called multiprogramming.

9 Moving into single user computers, we find the workstations. They are high-end personal computers, with powerful CPUs, a lot of RAM memory and with one or more high capacity graphics card. Workstations are usually dedicated to 3D design, engineering simulations, medical imaging or stock market analysis

10 The most common computer for the general public is the personal computer or PC. It s a general-purpose machine designed for endusers. They are relatively cheap and addressed to domestic and office users.

11 A PC suitable for mobile use is called a laptop or notebook. They integrate all the devices in a single body, with a low weight (usually under 3 kilos and some of them even around 1 kilogram). They are as powerful as desktop computers, but their expansion capacity is limited (basically, they can have less memory and smaller disks and don t have all the expansion ports that a desktop computer has).

12 Over the last few years tablets have become a replacement for laptops for users with high mobility requirements. Their small size, their touchscreen and very intuitive interfaces have contributed to its fast introduction, even for reluctant sectors. They are focused mainly in media consumption, information retrieval, gaming, and online communication.

13 Finally, at the end of the classification we can find smartphones. They are handheld computers that were born as a fusion of cell phones and personal digital assistants (PDA). They allow us to be permanently connected and they have a broad spectrum of applications: professional and productivity tools, education or leisure.

14 Other mobile devices as PDAs, GPS, or Portable Media Players (PMPs) are all small computers with a specific function. PDAs or Personal Data Assistants are handheld devices conceived to be a personal information manager. They became popular during the late nineties and early 2000 but now they have almost disappeared as their functionality has been incorporated in smartphones. Their main functions are to store personal information as telephone numbers, notes, photos and songs, to offer productivity tools as a calculator or an appointment book and to provide communication tools as or web access connecting to the Internet Portable GPS are handheld devices designed to give the user its current position and to provide navigation tools. As their function has also been integrated in smartphones, their popularity has diminished, but they still have niche

15 applications as trekking or car navigation. Portable media players, or PMP, are handheld devices designed to store and play audio, video and digital images of different format. They usually store the content in internal flash memory or external flash memory cards. Their function has also been integrated in modern smartphones, so their presence in the market has declined.

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