chapter 5-1
CD-ROM drive
A CD-ROM drive is a slot on the computer or external device into which you insert a disk. The most common types of optical storage media are CDs, DVDs, and Blu-ray Discs. You can add or delete data to a CD-RW after the disc has been burned.
random access storage device
A random access storage device lets a computer go directly to the needed information. The device does not have to search the entire medium to find data
read-only device
A read-only device can only read data from the storage medium; new data cannot be saved to it.
read/write device
A read/write device can read data from the storage medium, and can write data onto the medium as well.
sequential storage device
A sequential storage device requires the computer to scan from the beginning of the medium to the end until it finds the data it needs.
Storage Devices
A storage device is a piece of hardware that holds the storage medium, sends data to the medium, and retrieves data from the medium. Hard drives, flash drives, and CD and DVD drives are all examples of storage devices.
backup
An important use of storage media is making a backup of computer data. When you back up data, you copy the data to a different location for safekeeping.t
System Startup
Computer storage devices are a key part of a computer's startup process. Without a storage device to hold startup information permanently, a computer would not know what to do when you turned it on.
restore
If the original data is lost or damaged you can restore the data from the backup files.
Storage Media
In terms of storage, a medium is an object that physically holds data or program instructions. Flash drives, magnetic tapes, compact discs, DVDs, and Blu-ray Discs are examples of storage media. (The word media is the plural of medium.) One important use of storage media is for making a backup of computer data. When you back up data you copy the data to a different location for safekeeping. If the original data is lost or damaged, you can restore the data from the backup files.
Primary storage
It describes the main memory, or RAM, in a computer.
UEFI (Unified Extensible Firmware Interface)
Most Apple Macintosh computers and personal computers built to run Windows 8 and later use UEFI (Unified Extensible Firmware Interface) instead of BIOS.
Storage Versus Memory
New computer users sometimes get confused about temporary memory (RAM) and permanent storage (disks and disk drives). They will say "memory" when they actually mean to say "storage." Adding confusion, both are measured with the same units: bytes. One byte equals about 8 bits, or a single character. A kilobyte, or 1KB, is 1 thousand bytes. A megabyte, or 1MB, is 1 million bytes. A gigabyte, or 1GB, is 1 billion bytes. A terabyte, or 1TB, is 1 thousand billion bytes. A petabyte, or 1PB, is one million gigabytes.
Optical storage devices
Optical storage devices use laser beams to read information that has been stored on the reflective surface of a disc.
Storage devices
Storage devices are a computer's hardware components that retain data even after the power is turned off.
Basic Input/Output System BIOS
The Basic Input/Output System, or BIOS, is a set of programs, called firmware, that tells the computer equipment how to start up. The BIOS is permanently stored in special memory chips.
hard drive
The most common magnetic storage device installed in computers is a hard drive.
memory
computer memory typically means a set of chips that act as a temporary work space in the computer.
file
computer stores data and program instructions in a file, which is a collection of related information or program code that is given a unique name. An internal storage device is installed inside your computer. An external storage device is positioned outside of your computer. Read-only devices let users access information but not save it. Read/write devices let users access and save information to the device.
firmware
firmware, that tells the computer equipment how to start up. The BIOS is permanently stored in special memory chips.
Secondary storage
refers to devices that can store data permanently, such as a hard drive, flash drive, compact disc, DVD, or external hard drive. These devices are sometimes called archival storage devices due to the fact that you can store data for a long time. An archival storage device stores information that is not frequently used and may not be needed for years, if at all. Primary storage does not require user interaction. Secondary storage requires some user interaction.
