Revision notes Essay

Revision notes Essay

Hardware is a physical parts of the computer system – the parts that you can touch and see. A motherboard, a CPU, a keyboard and a monitor are all components of hardware Precisely what is Software? Applications are a collection of recommendations that can be ‘run’ on a computer system. These guidelines tell the computer what to do. Application is not a physical thing (but it can obviously be placed on a physical medium for instance a CD-ROM), it is just a bunch of rules. An operating system including Windows XP or perhaps Mac OPERATING-SYSTEM X, applications such as Microsoft company Word, and the instructions that control a robot are typical examples of software. The Difference Between Hardware and Software? Computer systems is the physical components that make up the computer program. Hardware can be useless devoid of software to operate on it. Application is instructions that tell computer hardware what to do. Application is useless except if there is components to run that on. For the computer system to be useful it has to consist of both hardware and software. Central Processing Unit (CPU) The CPU is definitely the ‘brain’ of the computer. Is it doesn't device that carries out computer software instructions. The Pentium cpu made by Intel is among the a PROCESSOR. CPUs usually plug into a large plug on the primary circuit table (the motherboard) of a laptop. They receive very hot when operating therefore usually have a large fan mounted on their top to keep all of them cool. Random Access Recollection (RAM) Randomly Access Storage (RAM) may be the part of the computer system that briefly stores the instructions that the computer is definitely running, as well as the data it can be processing. RAM is a risky storage device. Which means that if the computer’s power is definitely turned off the contents of RAM vanish and are shed. RAM, like the CPU, as well plugs directly into sockets within the motherboard. When a computer is within use, their RAM is going to contain Read-Only Memory (ROM) Read-Only Storage (ROM) is used in most computer systems to hold a small, special piece of software: the ‘boot up’ software. This computer software runs when the computer is usually switched on or ‘boots up’. The software checks the computer’s hardware after which loads the operating system. ROM is non-volatile storage. Which means that the data it has is never dropped, even if the electrical power is switched off. Graphical User Interface (GUI) A GUI is a great interface built around image (graphical) points. Windows happen to be regions of the screen used to display data. Icons are small pictures that are used to symbolize folders, application, etc . Selections are data of options the user can easily select from. A pointer is usually an arrow that can be moved around the display and is used to select things. Windows XP is definitely an example of a computer with a GUI. GUIs are quite easy to use due to the visual nature of the software – the user has plenty of visual indications as to what points do. Nevertheless , to display all the nice design required with a GUI requires a lot of calculating power thus quite a highly effective computer is required. Mainframe Computer A mainframe computer is actually a large computer system, often used simply by large businesses, in federal government offices, or perhaps by colleges. Mainframe computers are typically: Highly effective – they can process large numbers of data, in a short time. Large – they are often retained in special, air-conditioned bedrooms. Multi-user – they let several users (sometimes hundreds) to use the pc at the same time, linked via remote terminals (screens and keyboards). Laptop Computer A ‘laptop’ computer is a light, compact and portable PC. Laptops contain a rechargeable electric battery so that they can be used even when certainly not plugged in into a mains power supply. They also have a built-in FLAT SCREEN monitor. To make them since portable as it can be, most laptops try to avoid any sort of cable or perhaps wire. Instead of a mouse, a track mat is used. Rather than wired link with a network or inkjet printer, ‘wireless’ a radio station connections are being used. MICR Audience Magnetic Ink Character Acknowledgement (MICR) can be described as technology that allows details via bank cheques to be read into a computer system quickly and accurately. The cheque amount and bank-account number happen to be printed at the end of each bank cheque in special permanent magnet ink utilizing a special typeface. An MICR reader may detect these numbers. OMR Scanner Optic Mark Identification (OMR) is a technology that permits the data by a qmc (question multiple choice ) type form to be read quickly and accurately into a computer. Special OMR forms are used that have spaces that could be coloured in (usually using a pencil). A great OMR scanner can then find these represents. Common uses of OMR are multiple-choice exam response sheets and lottery number forms. OCR Scanner Optic Character Acknowledgement (OCR) can be described as software technology that can convert images of text into an actual textual content file that can then end up being edited, electronic. g. using word-processing software). The result is in the same way if the text message had been typed in by hand. OCR is typically applied after a page of a publication has been searched. The sought image of the page is then analyzed by OCR software program, which actively seeks recognizable notice shapes and generates a matching text data file. Advanced OCR software can recognize normal handwriting and also printed text – to describe it in called handwriting recognition. Sensors A sensor is a gadget that turns a real-world property (e. g. temperature) into data that a computer can method. Examples of detectors and the properties they detect are… A sensor actions a specific property data and sends a signal to the pc. Usually this is certainly an analogue signal therefore it needs to be converted into digital data for the computer to method. This is done using by an Analogue-to-Digital Converter (ADC). Sensors are being used extensively in monitoring / measuring as well as data logging systems, and also in laptop control systems. SensorWhat that Detects TemperatureTemperature LightLight / dark PressurePressure (e. g. someone located on it) MoistureDampness / drying Water-levelHow total / vacant a container is MovementMovement nearby ProximityHow close / far something is. Switch or perhaps buttonIf something is touching / pressing this Printers Dot-Matrix Printer A dot-matrix printer is named following the pattern (a grid or ‘matrix’) of dots applied when creating the paper printout. Dot-matrix produce quality is usually poor, the printers are noisy, and much better creating systems on the market. However , the dot-matrix printers are still employed in certain circumstances: Since the limits actually strike the paper, several ‘carbon-copies’ can be published in one go. One of this is airline tickets, which have a number of duplicate pages, all branded in one go. Printed mechanism is very cheap, as well as the inked frills last for a long period. So , wherever cheap, low-quality printouts will be required, dot-matrix machines are used. A good example is shop receipts. Ink jet Printer Low-cost, high-quality, full-color printing became available during the eighties due to the progress ink-jet machines. Ink-jet computer printers are very peaceful in use. Simply because have and so few going parts they are also cheap to manufacture and so cheap to buy. However , the ink is incredibly expensive to buy (this is usually how the inkjet printer companies generate their earnings! ) therefore the printers are expensive to use. Lazer Printer Laser printers are very complex products, and thus costly to buy. However they are very inexpensive to use. This is because they generate marks on paper using a excellent dust known as toner that is certainly relatively inexpensive to buy. Just one toner cartridge will often last for 5, 000-10, 000 pages of printing. The laser printing device uses a complicated system, concerning a lazer, to make the toner stick to the necessary parts of the paper. (This system is completely different to a dot-matrix or ink-jet, and you don’t need to know the facts. )The laserlight and toner system allows very fast stamping compared to additional printers (just a few seconds per page). Plotter Plotters generate hard copy in an exceedingly different way to printers. Instead of increasing text and pictures from small dots, plotters draw for the paper utilizing a pen. The pens will be held in a great arm which could lift the digital voice recorden up or down, and which can approach across the paper. The equip and dog pen create a sketching just like a individual could, nevertheless much more accurately and more quickly. Different female pens can be used to produce colored line images. Designers and architects often use plotters since they work with huge bits of paper, considerably bigger than anything an ordinary printer could work with… Why Back up Your Data? Should you delete a file by accident, your laptop or computer breaks, the laptop is stolen, or perhaps your business melts away to the floor, having a back-up copy implies that you have not lost your precious info. You can retrieve your lost files and continue doing work. Most businesses use personal computers to store extremely important data (customer records, economical information, models for goods, etc . ) If this kind of data is lost, the business enterprise could possibly have to close. Backing-up business data is essential. How Are Backups Produced? Personal back up copies of the data on your hard-drive can be manufactured by…Burning files to a CD-R. Copying data files to an exterior hard-drive. Replicating the data to another computer on a network. Businesses backup essential data by…Making replications of data very regularly. Employing large-capacity media such as magnet tape. Keeping old replications of backups, just in case. Robotizing the system in order that nobody does not remember to do it! Keeping backup media off-site (in case of fire or theft) What is a Network? A network is several computers, or perhaps other gadgets, connected with each other so that they can exchange data. By way of example a network allows personal computers to share data, users to message each other, a whole space of computers to share an individual printer, etc . Network contacts between pcs are typically constructed with cables (wires). However , connections can be created using radio indicators (wireless / wi-fi), cell phone lines (and modems) or maybe, for lengthy distances, through satellite backlinks. Local Area Network (LAN) An area Area Network is a network confined to 1 building or perhaps site. Often a LAN is known as a private network belonging to a great organisation or business. Because LANs will be geographically small , they usually use cables or low-power the airwaves (wireless) pertaining to the cable connections. Wireless Neighborhood Network (WLAN) A wireless LAN (WLAN) is actually a LAN that uses a radio station signals (WiFi) to connect computers instead of cabling. At the middle of the WIRELESS LOCAL AREA NETWORK is a wi-fi switch or router – a small box with 1 or 2 antennas protruding the back – used for mailing and receiving data to the computer systems. (Most laptops have an invisible antenna constructed into the case. )It is much more simple to use wireless cable connections instead of operating long wire connections all over a building. Nevertheless , WLANs will be more difficult to make secure as other people could also try to get connected to the wi-fi network. Therefore , it is very important to experience a good, hard-to-guess password pertaining to the WIRELESS LOCAL AREA NETWORK connections. Commonly, the range of your wireless connection is about 50m, but it is dependent how a large number of walls, and so forth are in the manner. Wide Area Network (WAN) A Wide Place Network is known as a network that extends over a large place. A WAN is often made by signing up for several LANs together, such as when a business that has offices in different countries links school LANs jointly. Because WANs are often geographically spread over large areas and links between computers will be over long distances, they often use quite exotic cable connections technologies: optical fibre (glass) cables, satellite television radio links, microwave a radio station links, etc . Topologies The term topology means ‘arrangement’, so when we speak about the topology of a network, we indicate how the different parts are organized and linked together. There are three common network topologies… Bus Network In this kind of network, a good, central cable, the ‘bus’ is used to get in touch all of the personal computers together. Each computer contains a short cable television linking that to the ‘bus’. A coach network…Is affordable to install (just one very long cable). Could be very slow since all personal computers share precisely the same cable when ever communicating. Will stop working when there is a break in the central coach cable. Ring Network In this type of network each computer is attached to a loop of cable television, the ‘ring’. (If you took a bus network and linked the ends of the tour bus cable jointly, you would possess a ring network. )A diamond ring network…Can handle a break inside the ring wire since most computers continue to be joined with each other (it is now a shuttle bus network) Star Network Through this type of network every computer system is connected to a central device. These devices passes text messages between computer systems. At the center of your star network you might make use of a hub (cheap, but slower) or a move (more expensive, but faster). A star network…Is very costly to install (you have to purchase lots of cable television and the central device)Is very fast since every computer possesses its own cable which usually it doesn’t need to share. Can handle a cracked cable (only one computer system will be affected). Will stop doing work if the central device destroys. Is the most common network topology. •Any computer system that is to be connected to a network must have a network interface card (NIC). Cabling are still utilized in most networks, rather than using only wireless, mainly because they can bring much more info per second, and are safer (less ready to accept hacking). •A hub is actually a device that connects a number of computers jointly to make a LOCAL AREA NETWORK. •A switch, like a centre, is a system that attaches a number of computers together to make a LAN. •A router can be described as network gadget that connects together two or more networks. One common use of a router should be to join a home or business network (LAN) online (WAN). •A proxy storage space is a laptop setup to talk about a resource, generally an Internet interconnection. A link is a network device that typically links together two different parts of a LAN. What is a Record? The set of info associated with a single object or perhaps person is known as a record. Just what Field, and what is a Discipline Name? You’ll see that all of our student’s documents contain the same items. These materials are referred to as fields. Each field includes a field identity. What is a Essential Field as well as Primary Crucial? It is very important that all record within a database can be individually identified. We need to make sure that when we access a record, we could accessing the correct one. Analogue to Digital Convertor (ADC) If you would like to attach a great analogue insight device into a digital system such as a computer, you will need a great analogue to digital convertor (ADC). Among a computer peripheral that requires a great ADC is a microphone. At the time you plug a microphone to a computer, you are actually insert it in an ADC which turns the egal signals through the microphone in to digital data that the pc can then process. Digital to Analogue Convertor (DAC) If you need to attach an analogue output device to a digital gadget such as a computer system, you will need a digital to advertising agency convertor (DAC). A good example of a pc peripheral that needs a DAC is a loudspeaker or headphones. When you connect a loudspeaker into a computer system, you are actually plugging that into a DAC, which will take digital data from the laptop and converts it into analogue signals which the loudspeaker then turns into audio. The Effect of those Devices upon Our Lives Consider the list of products above. Now try to envision living without them – cleansing your clothes manually ,! Life is a lot harder. Microprocessor-controlled products mean that we now have more free time to relax and revel in ourselves rather than doing household chores. We are able to communicate with persons very easily applying computers, cell phones, etc . We are able to become element of online social networks, making new friends with people from all over the world. Personal computers and Online connections mean that most of the tasks that involved us leaving the property, for example , shopping for music, outfits or meals, can now be done on-line. Buying online gives all of us more selection of products and will save you us time. It is also wonderful from those who are unable to get free from the house quickly, such as the elderly, or the disabled. Trailing Cabling Computer equipment is often attached to lots of wires: power, network, etc . In the event these cables are lying on the floor, they will cause people to trip over them. Option: Place cords inside wire ducts, or perhaps under the carpeting / floors Spilt Refreshments or Food If any liquid are spilt on electric powered equipment, this sort of a h a computer, it might result in harm to the equipment, or an electric distress to the user. Solution: Continue to keep drinks and food from computers Overloaded Power Sockets Plugging a lot of power cords into a outlet can result in the socket being inundated, overheating, and a fire beginning. Solution: By no means plug too many cables to a socket. Always be certain there are fireplace extinguishers local Heavy Things Falling A large number of items of computer system equipment are very heavy: CRT monitors, laser printers, etc . Heavy items can cause significant injury if they land on people. Solution: Be sure equipment is positioned on strong dining tables / cabinets •Use strong passwords to guard your user login bank account •Never reveal your sign in password to anyone else •Place a fire wall between your pc and any kind of network •Disconnect from networks when you are certainly not using them •Encrypt any sensitive information (just in case they will get in) Batch Finalizing It is often certainly not desirable to handle a set of info inputs right up until a certain quantity have occurred or a set time has passed. So they are stored until the program comes on the web to method the data in a single ‘batch’. The advantage of batch processing is that it is possible during less-busy times on the pc or jobs can be queued up in so that it will fairly discuss a calculating resource such as a super-computer. The key disadvantage of set processing is the time delay between collecting the suggestions data and having an outcome. It can also be aggravating to find out simply later a batch manage has failed as a result of a data type problem. Best of luck!

Related Essays