Data Flow Diagram

Software

Microsoft windows XP is an example of system software. 
System software refers to the files and programs that make up your computer's operating system. System files include libraries of functions, system services, drivers for printers and other hardware .System software controls a computer’s internal functioning, it also controls the monitor and speakers and also storage devices. The programs that are part of the system software include assemblers, compilers, file management tools, system utilites, and debuggers. The system software is installed on your computer when you install your operating system. You can update the software by running programs like "Windows Update" and "Software Update"

A word processor is an example of application software. Application software is also known as Apps. Application software is computer software that includes database programs, word processors, and spreadsheets these are all office applications, they allow us to make documents with text and pictures. there is other types of application software such as games software, games software is an "app" that you can design games on. Application software can not run with out operating software.

Software utilities are things like firewalls that protect our computers from virus. there are many types of software utilities such as firefox click and clean or Win HMR. these types of things keep our information secure and makesure know one can hack our computers or take personal information. firewalls also allow computers to preform tasks quicker because they are keeping harmful material from slowing the computers down.

Hardware components

The processor tells your computer what to do and when to do it, it decides which tasks are more important and prioritizes them to your computers needs.

RAM means ransom access memory. the RAM provides space for your computer to read and write data to be accessed by the CPU (central processing unit). The more RAM you have on your computer the faster the speed on your computer is.

devices for network connection

3G stands for third generation. it allows the signal to carry far larger amounts of data, this meant that 3G mobile phones could access the internet at reasonable speeds, it also allows you to use video calls on your phone. As 3G suggests there was 2 pervious generations before this. There are many application you can use if you have 3G such as mobile internet and mobile TV. 3G has higher data speed and enhanced audio and video streaming. To use 3G you need to subscribed to a service provider to get the network connectivity

There is also a 4G which means fourth generation is basically the extension in the 3G technology with more bandwidth and services offers in the 3G. With 4G you get ultra broadband internet access.  4G has data transmission speeds as high as100 Mbps. 4G can be used with mobile phones and wireless computers. 4G is a wireless broadband.

Bluetooth is a way of exchanging data wirelessly over short distances. Using a special radio frequency to transmit data, it creates a short range network. It is very secure and can connect up to eight devices at the same time. Bluetooth can be used for sending images, videos or music using a mobile phone with Bluetooth or a laptop with Bluetooth. Bluetooth is very secure as you have to accept a Bluetooth invitation if you want something to be sent to you or something of yours sent to others.

 

A network interface card (NIC) provides the hardware interface between a computer and a network. A NIC technically is network adapter hardware in the form factor of an add-in card such as a PCI or PCMCIA card.

Output Devices

A printer transferes text and pictures onto paper. A printer can print out in black and white or colour. a printer plugs into a usb slot. nowadays you can but a printer with a scanner attached to it.

a monitor is a screen that shows moving or still images that have been genarated by the computer and processed by the graphics card in the computer. there are two types of monitors which are CRT and LCD. a CRT (cathode- ray tube) are the most popular type of monitor and have been used for many years but they are quite bulky. An LCD (liquid crystal display) are energy eifficient and are compact, thin and lightweight.

speakers are used on a computer to give out sound. the speakers give off freaquancys that we can hear. speaks are normally built into the computer but you can also buy speakers that plug into your computer. speakers can also be used whilst you are using webcam because you will be able to hear the people you are talking to. speakers most commanly come with a volume control switch and a socket for headphones to plug into.

Storage devices

A hard disc drive is a storage device for digital data. it has one or more rotating rigid platters on a motor-driven spindle which is in a metal case. The data is enclosed magneticaly.

A memory stick is a removable flash memory card. it stores document or pictures of videos. they are small enough to carry around and can be used on any computer to transfere information.

A CD rom is a compact disc that contains data. it can only be used on a computer for visual aid of a video or on a radio for sound, it can not be written.

Different Types of Computer Systems

   

A PC is a personal computer, It is a small computer that is Based on a microprocessor that is made to be used by one person at a time.

A base unit is the main  part of the computer, it is where you incert CD's or discs.

a laptop is a portable computer that can be used whilst travelling. It is small and light enough to carry around.

 A net book is a small laptop that is smaller than a notebook. It is designed mainly for internet applications.

A P.D.A is a personal digital assistant. It is a device to store things like addresses and phone numbers.

 A mobile phone is a hand held mobile. It connects with telephone networks so that we are able to talk and text other people.

  game console is an interactive entertainment computer or computer system that produces a video display signal which can be used with a display device

 A server is a computer were all information is stored. It also runs programmes on computers that are on the same network. 

A tablet is a tablet-sized computer that also has the key features of a full-size personal computer, It is completely touch screen.

Embedded devices are small programmable chips that can be programmed to execute certain orders e.g. the control panel in an elevator is an embedded device.

input devices

The mouse is a pointing device that navigates a crusor across a comuter screen. there are usually two, sometimes three buttons on modern mouses that serve as selection buttons.

A micraphone is a device that converts sound waves into electiral signals that can be amplified, transmitted and output through speakers.

A graphics tablet allows the user to hand draw images or graphics. a graphics tablet is normally used by archutects.

A computer keyboard allows the user to input symbols, letters and numbers into th computer. the most popular keyboard is a QWERTY which is based on a typewriter.

  


A webcam is a camera that connects to the computer that sends images that can be seen by internet users. it can be used for taking pictures or making videos.








 








A scanner is a device that scans images onto a computer so that the user can view and edit them. a scanner only scans in black and white

A laser pen is something you can use with a graphics tablet. you can use it to control the tablet instead of using a keyboard or mouse.

A digital camera can take videos or still photographs. digital cameras produce digital photos that you can print or put online, by uploading onto the internet.

A mobile phone is a device that allows people to contact others via text message or call. you can also store music videos and photographs.

A game controller is a device used with games or entertainment systems used to control a playable character or object, or otherwise provide input in a computer game.