unit 1 IT

• router: allows multiple computers to join the same network (this can be through the ethernet ports or wirelessly)
• modem: connects to the internet service provider (ISP) either through cable, digital subscriber line (DSL) or fibre-optic internet service.
• hybrid: a modem and router combined into a single device; usually offered by ISPs to make the set-up process easier.
• network interface card: an expansion card that enables a computer to connect to a network using am ethernet cable ( most computers have a network interface built into the motherboard).
• wi-fi adapter: integrated as standard on new computers USB network adapters plug into a standard USB port.
• processor -> carries out the instructions of a computer program; it performs the mathematical, logical and input/output operations of a computer system.
• Memory in computers is categorized as RAM (random access memory) and ROM (read only memory).
• RAM is fast, volatile, and stores the operating system, applications, and graphical user interface.
• ROM is not volatile, cannot be changed by a program or a user, and stores the start-up instructions of the computer.
• Cache in computers is a high-speed memory in the CPU that speeds up access to data and instructions stored in RAM and holds frequently requested data and instructions so that they are available to the CPU when required.
• There are two types of cache: internet and external cache.
• name some operational issues organisations must take into consideration?

  security of information, health & safety, disaster and recovery, organisational policies, change management, scale of change; change drivers and change needs.
• operational issues:
• operational issues

  health & safety- physical protection on-site for staff and customers to be protected against hazards.
• operational issues

  disaster and recovery- prevent data loss in the event of an unexpected disaster.
• operational issues

  organisational policies- policies that outline acceptable computer and network use e.g. AUP.
• operational issues

  change management- formal approach to lead a change in the way a business or project is run.
• operational issues

  scale of change-

  change drivers- change to stay up to date with times and new technology

  change needs- change if needs and focus of the organisation are altered over time.
• what is the purpose of a motherboard?

  main circuit board of a computer which connects other computer components together such as the CPU and ROM.
• what is the purpose of a processor?

  manages the functions of a computer system by processing data and instructions.
• what is the purpose of a power supply unit?

  concerts electricity from AC from the mains power supply to DC which the computer system can use.
• what are the two types of memory?

  volatile and non-volatile.
• volatile- temporary( data is lost when power is turned off).
• non-volatile- saves data at all times and can be stored long-term.
• cache memory

  • volatile (temporary)
  • stores data that is frequently accessed
  • very quick to access because it is closer to the CPU
• read-only memory(RAM)

  • non-volatile, it cannot be changed
  • stores the boot program/BIOS
  • the BIOS loads up the operating system which takes over managing the computer.
• random access memory (RAM)

  • volatile (temporary)
  • stores all programs that are currently running
  • stores part of the operating system.
• secondary storage:

  magnetic

  • magnetic hard disc drive(HDD)
  • floppy disk, replaced by solid state devices e.g. USB
  • magnetic tape.
• magnetic tape has high storage capacity and is used by organisations to back up or archive large quantities of data.
• magnetic storage:

  • large capacity and cheaper per gigabyte than solid state disc.
  • not durable and not very portable when powered on- it can cause damage
  • relatively quick access speed but slower than solid state.
• what is a modem used for?


  a modem converts computers digital signal into analogue signal so that it can be transported along a telephone line and then converts it back into digital so the computer can use it.
• what is the purpose if a router?

  to transfer data packets between networks.

  they store the addresses of each computer in the network and uses routing tables to find the quickest and shortest route.
• what is the purpose of a wireless access point?

  creates a link between wireless and wired networks.

  creates a wireless local area network which allows wi-fi dependant devices to connect to a wired network.
• what is the purpose of a hybrid/combined device?

  provides the functionality of multiple communication devices in a single devices.

  more expensive than a single device

  more adaptable

  still functional if routing part of device fails.

  decreased performance than single device.
• what is the purpose of a network interface card?

  a piece of internal hardware that is required for computers to connect to a network.

  they are now commonly built directly into the motherboard, known as a network adapter).
• what is the purpose of a hub?

  receives data packets from a connected device and sends a copy of the data packet to all connected nodes.
• what is the purpose of a switch?

  receives data packets, processes them and transfers them onto the device specifically listed in the destination address of the data packet.
• troubleshooting tools

  • event viewer; lists detailed information about an error and when one occurs.
  • POST(power on self test); checks memory, power, hardware and cooling systems are working. beep codes signal if error has been detected
  • ping test: connectivity test. message sent and waits for an echo reply.