chapter 1 and 2 Intro to computers

The primary four operations of a computer are
input processing output and storage
Today’s computers also typically perform
communications functions
communication functions can include
sending or retrieving data via the Internet, accessing information located in a shared company database, or exchanging email messages.
define computer
A programmable, electronic device that accepts data input, performs processing operations on that data, and outputs and stores the results
define input
The process of entering data into a computer; can also refer to the data itself.
define processing
Performing operations on data that has been input into a computer to convert that input to output.
define output
The process of presenting the results of processing; can also refer to the results themselves.
define storage
The operation of saving data, programs, or output for future use.
define communication
The transmission of data from one device to another.
define data
Raw, unorganized facts.
define process
To modify data.
define information
Data that has been processed into a meaningful form.
A user inputs data into a computer, and then the computer
processes it.
When data is modified, or processed, into a meaningful form, it becomes
Any fact or set of facts can become
computer data
The physical parts of a computer (the parts you can touch) are called
the programs or instructions used to tell the computer hardware what to do and to allow people to use a computer to perform specific tasks.
Computer users are also called
end users
the people who use computers to perform tasks or obtain information are called
Computer users
computer professionals who write the programs that computers use are called
Other computer professionals include
Systems analysts Computer operations personnel Security specialists
a tiny computer embedded into a product designed to perform specific tasks or functions for that product.
embedded computer
data, applications, and even resources stored on computers accessed over the Internet—in a “cloud” of computers—rather than on users’ computers, and you access only what you need when you need it is called
cloud computing
very small device, typically pocket-sized, that has built-in computing or Internet capability.
mobile device
a small computer designed to be used by one person at a time
personal computer
Conventional personal computers that are designed to fit on or next to a desk are often referred to as
desktop computers
small personal computers that are designed to be carried around easily.
Portable computers
A device that must be connected to a network to perform processing or storage tasks is referred to as
dumb terminal
a thin client is also called a
network computer
a device that is designed to be used with a company network
thin client
define notebook computer (laptop computer)
A portable computer that is about the size of a paper notebook that is comparable to a desktop computer in features and capabilities.
define netbook
A portable computer about the size of a notebook that is designed to be used with a digital pen, a digital stylus, or touch input.
Network computers or other devices designed primarily for accessing the Internet and/or exchanging email are called
Internet appliances
a medium-sized computer used to host programs and data for a small network is
A midrange server
a midrange server is sometimes called a
One trend involving midrange servers, as well as the mainframe computers is called
is a powerful computer used in many large organizations that need to manage large amounts of centralized data is called a
mainframe computer
the most powerful and most expensive type of computer available is a
To reduce the cost, supercomputers are often built by connecting hundreds of smaller and less expensive computers into a
supercomputing cluster
the supercomputing cluster
acts as a single supercomputer.
a collection of computers and other devices that are connected to share hardware, software, and data, as well as to communicate electronically
A network
define internet
The largest and most well-known computer network, linking millions of computers all over the world
define Internet Service Provider (ISP)
A business or other organization that provides internet access to others, usually for a fee.
define World Wide Web (Web or WWW)
The collection of Web pages available through the Internet
define Web page
A document located on a Web server.
what uniquely identifies a Web page
A uniform resource locator (URL)
English names used to identify computers on the internet are called
Domain Name
Numeric addresses used to identify computers on the internet are
IP Address
define bit
The smallest unit of data that a binary computer can recognize.
define byte
Eight bits grouped together.
define file
A named collection of bytes that represent virtually any type of data
define system unit
The main case of a computer
All devices used with a computer need to be connected via a wired or wireless connection to the
External devices typically connect to the motherboard by plugging into a
define Circuit board
A thin board containing computer chips and other electronic components
define computer chip
A very small piece of silicon or other semiconducting material that contains the integrated circuits and transistors.
define motherboard
The main circuit board inside the system unit
define port
A connector on the exterior of the system unit case that is used to connect an external hardware device
Portable computers almost always contain a a rechargeable battery pack to
power the computer when it is not connected to a power outlet
Portable computers also almost always contain
an external power supply adapter that connects the computer to a power outlet to recharge the battery when needed.
make portable computers and mobile devices lighter.
Nonremovable batteries
are difficult and expensive to replace if they fail.
Nonremovable batteries
a computer chip that performs the calculations and comparisons needed for processing; it also controls the computer’s operations.
The central processing unit CPU
Most CPUs today are
multi-core CPUs
CPUs that contain the processing components or cores of multiple independent processors in a single CPU.
multi-core CPUs
measures of the number of instructions that can be processed per second.
The CPU clock speed
Multi core CPUs allow computers to
work on more than one task simultaneously.
a special group of very fast memory circuitry located on or close to the CPU that is used to speed up processing by storing the data and instructions that may be needed next by the CPU in handy locations.
Cache memory
chips located inside the system unit that the computer uses to store data and instructions while it is working with them.
is used to store the essential parts of the operating system while the computer is running, as well as the programs and data that the computer is currently using.
RAM or random access memory
high-speed memory built into the CPU that temporarily stores data during processing
consists of nonvolatile chips that permanently store data or programs.
ROM or read-only memory
consists of nonvolatile memory chips that the user or computer can use for storage
Flash memory
define Universal Serial Bus (USB)
A versatile bus architecture widely used for connecting peripheral devices.
define FireWire (IEEE 1394)
A high-speed bus standard used to connect devices—particularly multimedia devices like digital video cameras—to a computer.
an electronic path over which data can travel.
A bus
the connectors located on the exterior of the system unit that are used to connect external hardware devices.
Each port is attached to
the appropriate bus on the motherboard
Each port is attached to the appropriate bus on the motherboard so that when a device is plugged into a port
the device can communicate with the CPU and other computer components.
The key element of the CPU is the
transistor—a device made of semiconductor material that controls the flow of electrons inside a chip.
the section of a CPU core that performs arithmetic involving integers and logical operations.
The arithmetic/logic unit (ALU)
Arithmetic requiring decimals is usually performed by the
floating point unit (FPU).
To synchronize all of a computer’s operations what is used
a system clock
what is a system clock
a small quartz crystal located on the motherboard
Whenever the CPU processes a single basic instruction, it is referred to as
machine cycle.
The part of a CPU core that attempts to retrieve data and instructions before they are needed for processing to avoid delays
Prefetch unit
The part of a CPU core that translates instructions into a form that can be processed by the ALU and FPU
Decode unit
The section of a CPU core that allows the core to communicate with other CPU components
Bus interface unit
With the exception of computers
designed to use only network storage devices, virtually all personal computers come with a
hard drive
used to store most programs and data.
hard drive
contain one or more metal hard disks or platters that are coated with a magnetizable substance.
Magnetic hard drives
a hard drive that uses flash memory technology instead of spinning hard disk platters and magnetic technology.
solid-state drive (SSD, also called flash memory hard drives)
Hard drives can be
internal or external
The total time that it takes for a hard drive to read or write data is called
the disk access time
the disk access time requires what 3 things
seek time rotational delay data movement time
The read/write heads move to the cylinder that contains (or will contain) the desired data.
Seek time
The hard disks rotate into the proper position so that the read/write heads are located over the part of the cylinder to be used.
Rotational delay
The data moves, such as reading the data from the hard disk and transfer- ring it to memory, or transfers from memory and is stored on the hard disk.
Data movement time
stores copies of data or programs that are located on the hard drive and that might be needed soon in memory chips to avoid having to retrieve the data or programs from the hard drive when they are requested.
A disk cache
essentially a combination flash memory/magnetic hard
Hybrid hard drives
thin circular discs made out of polycarbonate substrate that are topped with layers of other materials and coatings used to store data and protect the disc.
Optical discs
Optical discs are designed to be read by
optical drives,
a chip-based storage medium that represents data using electrical charges.
Flash memory
flash memory chips embedded into products.
Embedded flash memory
One of the most common types of flash memory media is
flash memory card
small, rectangular card containing one or more flash memory chips, a controller chip, other electrical components, and metal contacts to connect the card to the device or reader with which it is being used.
flash memory card
) consist of flash memory media integrated into a self-contained unit that connects to a computer or other device via a standard USB port and is powered via the USB port.
USB flash drives
using a storage device that is not connected directly to the user’s computer; instead, the device is accessed through a local network or through the Internet.
Remote storage
Remote storage devices accessed via the Internet are often referred to as
online storage or cloud storage
A high-performance storage system connected individually to a network to provide storage for computers on that network
A network of hard drives or other storage devices that provide storage for another network
A network of hard drives or other storage devices that provide storage for another network
Storage area network (SAN)
a credit card-sized piece of plastic that contains computer circuitry and components—typically a processor, memory, and storage.
A smart card
A method of storing data on two or more hard drives that work together.
RAID (redundant array of independent disks)
Storage media consisting of plastic tape coated with a magnetizable substance.
Magnetic tape
For large computer systems, instead of finding a single hard drive installed within the system unit, you are most likely to find
a large storage system (sometimes called a storage server).
Most storage servers are based on
on magnetic hard disks
Most computers today are designed to be used with a
a device containing keys used to enter characters on the screen
used to select and manipulate objects, to input certain types of data, such as handwritten data, and to issue commands to the computer.
Pointing devices
most common pointing device for a desktop computer.
The mouse
An input device that moves an on-screen pointer used to select and manipulate objects and to issue commands to the computer.
Pointing device
A pointing device similar to an upside-down mouse with the ball mechanism on top.
A penlike device used by writing, drawing, or tapping on the screen.
Stylus (digital pen)
allow the user to touch the screen with his or her finger as a pointing device to select commands or otherwise provide input to the computer associated with the touch screen.
Touch screens
a rectangular pad across which a fingertip or thumb slides to move the on-screen pointer; tapping the touch pad typically performs clicks and other mouse actions.
touch pad
captures an image of an object in digital form, and then transfers that data to a computer.
The quality of scanned images is indicated by
optical resolution
optical resolution is usually measured in the number of
pixels per inch (ppi).
an optical code that represents data with bars of varying widths or heights.
is a technology that can store, read, and transmit data located in RFID tags.
Radio frequency identification (RFID)
contain tiny chips and radio antennas; they can be attached to objects, such as products, price tags, shipping labels, ID cards, assets, and more.
RFID tags
The data in RFID tags is read by
RFID readers.
used to read biometric data about a person so that the individual’s identity can be verified based on a particular unique physiological characteristic
Biometric reader
Most computers today use the thinner and lighter
flat-panel displays
smallest colorable area on a display device.
Flat-panel technologies include what 4 things
Liquid crystal display (LCD) Light emitting diode (LED) Organic light emitting diode (OLED) Plasma display
the most energy efficient flat panel technology is
Organic light emitting diode
Common Display Interfaces include what 4 things
HDMI DVI VGA Display Port
printers produce
a hard copy
is a permanent copy of output on paper.
a hard copy
A printer that uses molten plastic during a series of passes to build a 3D version of the desired output.
3D printer
A printer used to print barcodes.
Barcode printer
A permanent copy of an output on paper.
Hard copy
An output device that forms images by spraying tiny drops of liquid ink from one or more ink cartridges onto paper.
Ink-jet printer
An output device that forms images with toner powder (essentially ink powder).
Laser printer
An output device that can copy, scan, fax, and print documents.
Multifunction device (MFD)
The typical measurement of print speed.
Pages per minute (ppm)
A small, lightweight printer that can be used on the go, such as with a notebook or a mobile device.
Portable printer