| Term | Definition |
| access speed | time required to retrieve data from a secondary storage device. |
| Blu-ray disc (BD) | designed to store hi def (high definition) video; typical storage 50 GB; often used to store hi def video and video games. |
| capacity | measures how much a particular storage medium can hold. |
| compact disc (CD) | were the first widely available optical format for PC users. Typically, CD drives store 700 MB (megabytes) of storage. Optical discs that store music are often CDs. |
| cloud computing | where the Internet acts as a “cloud” of servers that supply applications to clients as a service rather than a product. |
| cloud storage | cloud computing, where the Internet acts as a “cloud” of servers that supply applications to clients as a service rather than a product. Additionally, these servers provide, also known as online storage. |
| cylinder | run through each track of a stack of platters. |
| density | refers to how tightly these charges can be packed |
| disaster recovery specialist | are responsible for recovering systems and data after a disaster strikes an organization. |
| disk caching | improves hard-disk performance by anticipating data needs. |
| digital versatile disc or digital video disc (DVD) | are the standard optical discs in PCs. DVDs are very similar to CDs except that these discs can store 4.7 GB (gigabytes)—seven times the capacity of CDs. Optical discs that store movies or software |
| enterprise storage system | to promote efficient and safe use of data across the networks within their organizations. |
| external hard drive | use the same basic technology as internal hard disks and are used primarily to complement an internal hard disk. Because they are easily removed, they are particularly useful to protect or secure sensitive information. |
| file compression | increase storage capacity by reducing the amount of space required to store data and programs. |
| file decompression | increase storage capacity by reducing the amount of space required to store data and programs. |
| file server | dedicated computers with very large storage capacities that provide users access to fast storage and retrieval of data |
| flash memory | Solid-state storage devices provide access to, also known as solid-state storage |
| flash memory card | are small solid-state storage devices widely used in portable devices. Some of the cards are used within devices such as laptops, smartphones, and GPS navigation systems. |
| hard disk | use rigid metallic platters that provide a large amount of capacity. |
| head crash | occurs when a read-write head makes contact with the hard disk’s surface or with particles on its surface |
| hi def (high definition) | uses the HD 720 and HD 1080 resolutions |
| internal hard disk | located inside the system unit. These hard disks are able to store and retrieve large quantities of information quickly. |
| land | The 1s and 0s are represented by flat areas |
| mass storage | refers to the tremendous amount of secondary storage required by large organizations |
| mass storage devices | are specialized high-capacity secondary storage devices designed to meet organizational demands for data storage. |
| media | are the physical material that holds the data and programs. |
| network attached storage (NAS) | a type of file server designed for homes and small businesses. is less expensive, easier to set up, and easier to manage than most file servers. However, it does not include powerful management tools and features found in many large-scale file servers. |
| optical disc | can hold over 128 gigabytes of data. |
| optical disc drive | read by using a laser that projects a tiny beam of light on these areas |
| organizational cloud storage | high-speed Internet connection to a dedicated remote storage facility. These facilities contain banks of file servers to offer enormous amounts of storage. |
| pit | bumpy areas on disc surface |
| platter | are stacked one on top of another. |
| primary storage | RAM is sometimes referred to as |
| RAID system | larger versions of the specialized devices discussed earlier in this chapter that enhance organizational security by constantly making backup copies of files moving across the organization’s networks. |
| read-only memory (ROM) disc | are discs that cannot be written on or erased by the user. Optical discs that you buy in a store, such as music CDs, DVD movies, and Blu-ray video games, are often read only. |
| redundant array of inexpensive disks (RAID) | improve performance by expanding external storage, improving access speed, and providing reliable storage. |
| rewritable (RW) disc | are similar to write-once discs except that the disc surface is not permanently altered when data is recorded. These changeable, portable storage options are popular for storing and sharing audio, video, and large multimedia presentations. |
| secondary storage | provides nonvolatile storage, and retains data and information after the computer system is turned off. |
| secondary storage device | provides permanent or nonvolatile storage |
| sector | wedge-shaped sections. |
| solid-state drive (SSD) | are designed to be connected inside a personal computer system the same way an internal hard disk would be but contain solid-state memory instead of magnetic disks to store data. |
| solid-state storage | devices have no moving parts. Data and information are stored and retrieved electronically directly from these devices much as they would be from conventional computer memory. |
| storage area network (SAN) | is an architecture to link remote computer storage devices, such as enterprise storage systems, to computers such that the devices are as available as locally attached drives. |
| storage device | are hardware that reads data and programs from storage media. Most also write to storage media. |
| track | concentric rings on the platter. |
| USB drive | so compact that they can be transported on a key ring. These drives conveniently connect directly to a computer’s USB port to transfer files and can have capacities ranging from 1 GB to 256 GB, with a broad price range to match, also known as flash drive |
| write-once disc (R) | can be written on once. After that, the disc can be read many times but cannot be written on or erased. These discs are ideal for creating permanent archives, such as CD-R, often used for storing family photos, and DVD-R, often used to store home movies. |
