Discovering Computers 2018 Digital Technology, Data, and Devices PDF

# Discovering Computers 2018 - Digital Technology, Data, and Devices ## Module 8: Digital Storage: Preserving Content Locally and on the Cloud ### Objectives Overview (1 of 2 ) - Differentiate between storage and memory - Describe the characteristics of internal hard disks - Describe the benefits...

# Discovering Computers 2018 - Digital Technology, Data, and Devices ## Module 8: Digital Storage: Preserving Content Locally and on the Cloud ### Objectives Overview (1 of 2 ) - Differentiate between storage and memory - Describe the characteristics of internal hard disks - Describe the benefits of solid-state drives - Identify uses of external hard drives and RAID - Differentiate among the various types of memory cards and USB flash drives ### Objectives Overview (2 of 2 ) - Discuss the benefits and uses of cloud storage - Describe characteristics of and differentiate among types of optical discs - Explain types of enterprise storage - Identify uses of magnetic stripe cards, smart cards, RFID tags, and NFC tags ### Storage (1 of 10) - A storage medium is the physical material on which a computer keeps data, information, programs, and applications. - Cloud storage keeps information on servers on the internet, and the actual media on which the files are stored are transparent to the user. ### Storage (2 of 10) - A diagram shows a variety of storage options: - Internal solid state drive - Internal hard drive - Memory cards - USB flash drive - NFC tags - RFID tags - Smart card - Magnetic stripe card - Optical discs - Network attached storage device - Cloud storage ### Storage (3 of 10) - A storage device is the hardware that records and/or retrieves items from storage media. - **Reading** is the process of transferring items from a storage medium into memory. - **Writing** is the process of transferring items from memory to a storage medium. ### Storage (4 of 10) - **Capacity** is the number of bytes that a storage medium can hold - A table shows the terms used to define storage and the exact and approximate number of bytes in each. |Storage Term|Approximate Number of Bytes|Exact Number of Bytes| |:---|:---|:---| |Kilobyte (KB)|1 thousand|2^10 or 1,024| |Megabyte (MB)|1 million|2^20 or 1,048,576| |Gigabyte (GB)|1 billion|2^30 or 1,073,741,824| |Terabyte (TB)|1 trillion|2^40 or 1,099,511,627,776| |Petabyte (PB)|1 quadrillion|2^50 or 1,125,899,906,842,624| |Exabyte (EB)|1 quintillion|2^60 or 1,152,921,504,606,846,976| |Zettabyte (ZB)|1 sextillion|2^70 or 1,180,591,620,717,411,303,424| |Yottabyte (YB)|1 septillion|2^80 or 1,208,925,819,614,629,174,706,176| ### Storage (5 of 10) - A diagram shows a computer switch that is ON and another switch that is OFF. - A screen display is considered volatile because its contents disappear when power is removed. - Likewise, most RAM is volatile. That is, its contents are erased when power is removed from a computer or mobile device. Storage, by contrast, is nonvolatile. Its contents remain when power is off. ### Storage (6 of 10) - A diagram shows two screen displaying the same spreadsheet. - A screen display is considered volatile because its contents disappear when power is removed. - Likewise, most RAM is volatile. That is, its contents are erased when power is removed from a computer or mobile device. Storage, by contrast, is nonvolatile. Its contents remain when power is off. ### Storage (7 of 10) - A diagram shows two RAM chips with a receipt image displayed. - A screen display is considered volatile because its contents disappear when power is removed. - Likewise, most RAM is volatile. That is, its contents are erased when power is removed from a computer or mobile device. Storage, by contrast, is nonvolatile. Its contents remain when power is off. ### Storage (8 of 10) - A diagram shows two DVD discs with items from a receipt displayed. - A screen display is considered volatile because its contents disappear when power is removed. - Likewise, most RAM is volatile. That is, its contents are erased when power is removed from a computer or mobile device. Storage, by contrast, is nonvolatile. Its contents remain when power is off. ### Storage (9 of 10) - **Access time** measures: - The amount of time it takes a storage device to locate an item on a storage medium - The time required to deliver a item from memory to the processor ### Storage (10 of 10) - A diagram compares memory and storage in terms of transfer rates and the types of data stored. |Type|Transfer Rates|Stores| |:---|:---|:---| |Memory (most RAM)|Faster|Currently running programs and information they require, contents of screen display; commands sent between components of the computer, such as hard drive, processor, and video card| |Storage|Slower| |SSD| |Operating system, applications, user data and information; including photos,music, and video backups| |Hard Disks| |Operating system, applications, user data and information; including photos, music, and video backups| |USB Flash Drives| |Digital photos or files to be transported| |Memory Cards| |Digital photos or files to be transported| |Optical Discs| |Software, movies, music| - A comparison of different types of storage media and memory in terms of relative speed and uses. Memory is faster than storage but is expensive and not practical for all storage requirements. Storage is less expensive but is slower than memory. ### Hard Drives (1 of 11) - A **hard disk**, also called **hard disk drive (HDD)**, contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information. ### Hard Drives (2 of 11) - A diagram shows close up views of a hard drive mounted inside a laptop and another inside a desktop computer. - The hard disk in a personal computer is enclosed inside an airtight, sealed case. In these photos of the desktop and laptop hard disks, the top plate is removed for illustration purposes. The laptop hard disk is much smaller than the desktop hard disk. ### Hard Drives (3 of 11) - The storage capacity of hard disks varies and is determined by: - The number of platters the hard disk contains - The composition of the magnetic coating on the platters - Whether the disk uses longitudinal or perpendicular recording - Density ### Hard Drives (4 of 11) - A diagram shows a hard drive disc and shows the tracks and sectors formed on the disc. - **Formatting** is the process of dividing the disk into tracks and sectors. - Tracks form circles on the surface of a hard disk. The disk's storage locations are divided into wedge-shaped sections, which break the tracks into small arcs called sectors. Several sectors form a cluster. ### Hard Drives (5 of 11) - Characteristics of a hard disk include: - Tracks - Sectors - Platters - Form factor - Read/write head - Revolutions per minute ### Hard Drives (6 of 11) - A diagram shows a hard drive showing steps 1-4 of how a hard disk works. - The circuit board controls movement of the read/write head and motor. - A small motor spins the platters while the computer is running. - Software requests access to data and read/write heads determine the current or new location of the data - Read/write head actuator positions read/write head over the correct location on the platters to read or write ### Hard Drives (7 of 11) - A **head crash** occurs when the read/write head touches the surface of the platter. - Always keep a backup of your hard disk. - A diagram shows a close up view of a read/write head with a distance between the head and the platter and shows particles of dust, smoke, and hair floating above a platter. - The clearance between a hard disk read/write head and the platter is about two-millionths of an inch. Any contaminant could render the disk unusable. ### Hard Drives (8 of 11) - An **SSD (solid state drive)** is a flash memory storage device that contains its own processor to manage its storage. - An **SSD (Solid State Drive)** has several advantages over traditional (magnetic) hard disks: - Faster access times - Faster transfer rates - Quieter operation - More durable - Lighter weight - Less power consumption - Less heat generation - Longer life - Defragmentation not required ### Hard Drives (9 of 11) - An **external hard drive** is a separate freestanding storage device that connects with a cable to a USB port or another port on a computer or mobile device. - A diagram shows a laptop connected to a USB port on an external hard drive. - Examples of external hard drives. ### Hard Drives (10 of 11) - **RAID (redundant array of independent disks)** is a group of two or more integrated hard drives. - A diagram shows a laptop connected to a RAID storage drive. - An example of RAID for the home or small business user. ### Portable Flash Memory Storage (1 of 5) - A **memory card** is a removable flash memory storage device that you insert and remove from a slot in a computer, mobile device, or card reader/writer. - Types of memory cards: - SDHC - SDXC - miniSD - microSDHC ### Portable Flash Memory Storage (2 of 5) - Types of memory cards: - microSDXC - CF - XD Picture Card - Memory Stick PRO Duo - M2 ### Portable Flash Memory Storage (3 of 5) - A diagram shows a network of storage devices with memory cards that are used in laptops, tablets, printers, smartphones, and digital cameras. - Many types of computers and devices have slots for memory cards. ### Portable Flash Memory Storage (4 of 5) - A diagram shows how an SD card works, with steps 1-4. - When you insert a memory card into a card reader/writer, the metal connectors on the card reader/writer contain with contacts in the card and other devices, allowing for the transfer of information or items between the card and the receiving device. - Flash memory chips store photos and other types of data along with the files that contain the data. - A latch on the side of the memory card prevents the card from accidentally slipping out of the card reader/writer or card slot. - Flash memory chips store photos and other types of data along with the files that contain the data. - Using registers for temporary storage, as needed. ### Portable Flash Memory Storage (5 of 5) - **USB flash drives** plug into a USB port on computer or mobile device. - A diagram shows a close-up view of a USB flash drive. - A close-up of the flash memory and circuitry inside a USB flash drive. ### Cloud Storage - **Cloud storage** is an Internet service that provides storage to computer of mobile device users. - A diagram shows a network of devices (phone, desktop, tablet, laptop, etc.) connected to a cloud storage server. ### Optical Discs (1 of 5) - An **optical disc** consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser. - A diagram shows an optical disc in a disc drive. - An optical disc in a disc drive. ### Optical Discs (2 of 5) - A diagram shows steps 1-3 showing a laser reading data on an optical disc. - A laser diode shines a beam of light toward the disc. - If light strikes a pit it scatters, reflecting back toward the laser diode. - If light strikes a land it is deflected to a sensing diode, which sends a digital signal of 1 to the computer because light is reflected. Absence of reflected light is read as a digital signal pf 0. - This figure shows how a laser reads data on an optical disc. ### Optical Discs (3 of 5) - Optical discs commonly store items in a single track that spirals from the center of the disc to the edge of the disc. - A diagram shows a series of concentric circles on an optical disc. - A track is divided into evenly sized sectors. - An optical disc typically stores data, instructions, and information in a single track that spirals from the center of the disc to the edge of the disc. ### Optical Discs (4 of 5) - A **CD-ROM** can be read from but not written to. - Single-session disc - A **CD-R** is an optical disc which users can write once, but not erase. - A **CD-RW** is an erasable multisession disc. ### Optical Discs (5 of 5) - A **DVD-ROM** is a high-capacity optical disc on which users can read but not write on or erase. - A **DVD-R** or **DVD+R** are competing DVD recordable WORM formats, on which users can write once, but not erase. - **DVD-RW**, **DVD+RW**, and **DVD+RAM** are competing DVD-rewritable formats that users can write to on multiple times. ### Enterprise Storage (1 of 7) - Enterprise hardware allows large organizations to manage and store data and information using devices intended for heavy use, maximum efficiency, and maximum availability. - **RAID** duplicates data, instructions, and information to improve data reliability. ### Enterprise Storage (2 of 7) - A diagram shows two configurations of a RAID system: mirroring (RAID level 1) and striping. - In **RAID level 1**, called **mirroring**, a backup disk exists for each drive. - Other **RAID** levels use **striping**, that is, portions of each drive are placed on multiple drives. ### Enterprise Storage (3 of 7) - **Network attached storage (NAS)** is a server that is placed on a network with the sole purpose of providing storage to users, computers, and devices attached to the network. ### Enterprise Storage (4 of 7) - A diagram shows a network with one or more servers and two network attached storage devices. - An example of how network attached storage connects on a network. ### Enterprise Storage (5 of 7) - A **storage area network (SAN)** is a high-speed network with the sole purpose of providing storage to other attached servers. - A diagram shows a network with one or more servers and a storage area network. - A storage area network provides centralized storage for servers and networks. ### Enterprise Storage (6 of 7) - **Tape** is a magnetically coated ribbon of plastic capable of storing large amounts of data and information. - A **tape drive** reads and writes data and information on a magnetic tape. ### Enterprise Storage (7 of 7) - A diagram shows a tape robot retrieving a tape cartridge from a tape library. - A tape robot retrieves tape cartridges. ### Other Types of Storage (1 of 7) - A **magnetic stripe card** has a magnetic stripe that contains information. - A **smart card** stores data on an integrated circuit embedded in the card. ### Other Types of Storage (2 of 7) - A diagram shows a credit card and shows a close up view of the magnetic stripe on the back of the card. - The magnetic stripe on the back of credit cards and other ID cards contain information that identifies you and the card. ### Other Types of Storage (3 of 7) - A diagram shows a person using a contact smart card reader and another person using a contactless smart card reader. - Examples of contact and contactless smart cards and their readers. ### Other Types of Storage (4 of 7) - The **RFID tag** consists of an antenna and a memory chip that contains the information to be transmitted via radio waves. - An **RFID reader** reads the radio signal and transfers the information to a computer or computing device. ### Other Types of Storage (5 of 7) - A diagram shows an RFID reader and tag attached to a box. - An RFID reader reads radio signals from an RFID tag that is affixed to this box. ### Other Types of Storage (6 of 7) - An **NFC-enabled device** contains an NFC chip. - An **NFC tag** contains a chip and an antenna that contains information to be transmitted. - Most **NFC tags** are self-adhesive. ### Other Types of Storage (7 of 7) - A diagram shows a person using a contactless phone to make a mobile payment. - This NFC-enabled phone communicates with the NFC reader to send a mobile payment. ### Summary - Variety of storage options. - Storage capacity and storage access time. - Characteristics of hard disks, SSDs, external hard drives, and RAID. - Portable flash memory storage - Advantages and various uses of cloud storage - Characteristics of optical discs. - Enterprise storage options - Magnetic stripe cards, smart cards, RFID tags, and NFC chips and tags