chapter 9

Modulation
Demodulation
Bandwidth
TCP/IP
Node
Client
Server
Network Operating Systems
Network Administrator

• Modulation

Is a process of inflection high-frequency periodic waveform,in music it inflect the volume,pitch and sort to enable the signal to transport all the information in the modulation signal to a particular destination.

• Demodulation

Is a process to extracting the original content signal from a modulated signal.Commonly used in connection that relate to radio receivers and modem.

• Bandwith

Is a rate or amount of data that can be transfer in one time.

Usually expressed in bits/second,and also bytes/second.

It is really important for i/o devices.

• TCP/IP

Is a short term for Transmission Control Protocol/Internet Protocol.

It's a set of general guidelines that is used to provide specific networking protocols that enables communicating with the network.

It has a variety types of communication services between computers.

• Node

Node is a connection point or processing location.

It is different depends on the protocol layered and the networks.it can be either computer or other devices such as printers.Each node has it own unique network address.It's also can be use to recieve,send and forward informations over a communication channel.

• Client 

Is an application which access remote service on other computer.

usually applied to a device that cannot stand by their own and need a connection to a remote server to run.

• Server

Is a device on a network that work to manage the resources .

There are a lot of different type server:

File server:a computer that is used to storing data.can be use by any user to store file to the server.

Printer server:a computer that manage one or more printers.

base server:a computer which manage other computers in the same network.

• Network Operating System

NOS which is an operating system that has a special function to connect computers and devices to a local-area network  (LAN).

It enable the server to manage user,security,groups,data,application and also other functions.

• Network administrator

Is the person who is responsible to manage the maintenance of the computer hardware and software.

Network admin work in an situation which is not involving direct user support.

It's more focuses on the integrity of the workers,server deployment,and security

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Secondary Storage

Disk Caching
File compression
File Decompression
Internet Hard Drive
Optical Disk Drive
Solid-state Storage

• Disk Caching

IS a part of RAM which is used to enhance the speed to access data on a disk.It works by storing all the frequent access data in the RAM cache.This will increase the performance of the cache.

• File Compression

Is a process which the data is reduced than the original.Reduced the uses of memory space in the hard disk and etc.

Usually used to make data transfer faster.The user that want to use the data need to decompress the data first using related software.

• File Decompression

Is the reverse process of compressing file.It decoding what is in the data.

Using software such as 7- zip program,user can open the date that have been compressed.

• Internet Hard Drive

User can used internet hard drive to store data.The data can be access as long as user have internet access using any computer.

The drawbacks is ,it may take a longer time to upload the data,larger file will take longer time duration.

• Optical Disk Drive

a storage medium which is used to read the data which is written by lasers.It has a large storing capacity up to 6 gigabytes.Most of optical drives can read numbers of formats such as CD-ROM ,CD-R and etc.

• Solid-state Storage

SSD is a storage device that has no moving parts.Contain DRAM or EEPROM ,a CPU.battery card and a memory bus board.It providing faster access because it have their own CPU to maneage the data storage.

Input and Output

ergonomic keyboard
ink jet printer
laser printer
magnetic ink character
optical character recognition
optical mark recognotion

• Ergonomic Keyboard

Is a keyboard which have 2 separated part with a V shape.
Design to reduced the muscle pain and less stress on the user hands.
Has two different desingn,fixed and separated.

• Ink Jet printer

Is one type of printer that people use the most.Use ink to create a digital image on paper.
Have a wide range from small , orlarge for professionla use and different prices.

• Laser Printer

Is a printer that used laser to print image which produces high quality result.
Range from 300 dpi at the low end at 1200 or 2400 dpi at the high end.

• Magnetic ink character

is a character recognition technology that enable computers read the information that can also easily read by human.Mainly used in banking,because machine can read a magnetic-ink with a greater accuracy.

• optical character recognition

Known as OCR,it involves reading text such as handwritten,printed text and typewritten into a form that can be manipulated by computer.Usually used to convert things such as book and documents and then edit it using word processor.

• optical mark recognotion

Known a OMR,the functions of optical mark recognition is  extracting data from marks fields on a printed forms.OMR technology scans a printed form and reads predefined positions and records where marks are made on the form.

RAM or known as random access memory,a type of computer data storage that takes form of the intergrated circuits that can be accessed randomly,commonly associated with volatile types of memory such as DAM memory modules,where it will store information if the power is off.


Cache: is a computer component that stores data transparently ,so that any request for the stored data can be access faster.data stored in cache might be computed earlier or duplicates of original vaalues that are stored elsewehere,cacahes are relatively small,so it is cost efficient.

Read only memory(ROM) is a storage medium used in computer and electronic devices which the data is already prerecorded.Different from the main memory(RAM),itholds it own data@contents even when the computer is turned off.The data stored in ROM can be modified in slowly speed or with difficulty,so the main purpose of ROM is it mainly used to distribute firmware.

Flash memory:
is a type of computer storage chip that is widely used,it is a memory that maintains stored information,it can be electrically erased and reprogrammed.it is used in memory card, USB flashdrivers,MP3 players and solid-state drivers for general storage.It cost far less compared to byte-programmable EEPROM .

Graphic Card
Graphic card is a part of hardware that is used to rendering the image on the compute'rs monitor or a display screen.this card usually offer added function,usually has a small amount of embedded memory and takes some of the main memory(RAM) ,it reduce the RAM available.

Sound Card:
Sound card or audio card is a an internal computer expansion card that stored input and output of audio signals.
also applied to external audio interface which use software to generate sound ,it is also providing the audio component for multimedia application.

Network Interface Card:
Is a hardware component that is used to connects a computer to a computer network.Usually implemented on expension card,then plug into a computer bus.

Plug and Play:
Is the ability to automatically configure expansion boards and other devices by a computer system it discover the hardware in the system,without need for a physical configuration.

Universal Serial Bus Port (USB):
is an external bus port which is used to establish communication between devices and host controller,which is effectively replaced earlier interfaces for example serial and parallel ports.
It can connect to com[puter peripherals such mice,modem,keyboard and also supports plug and play and hot plugging.

Serial Port:
Is a port,serial communication physical interface through which the information transfers in or out which only one bit is transmitted at a time.hardware more or less compliant to the RS-232 standard, intended to interface with  or communication device and modem.

Parallel port:
parallel communication physical interface it is an interface that is found in computers for connecting a wide range of peripherals.also known as the printer port or centronics port.

Firewire Port:
Is a form of serial port that transfer data with high speed from one device to another by using firewire technology.
it has the capability to interact with numbers of devices,it has lower implementation cost and more adaptable cabling system.

Ethernet Port:
Is a frame-based computer networking technologies,for local area networks (LAN),its involved a lot of wiring signaling standards for the physical layer of the standard networking model .
Also called as jacks or sockets.

High Definition Multimedia Interface Port:
Is an audio or video interface that is used to transmit uncompressed digital data,is an alternative to analog standards,support single cable,uncompressed  PC or TV  video format.