Chapter 8 : Digital Storage

Storage

A storage medium is the physical material on which a computer keeps data, information, programs, and applications. To keep our data or information safe, we usually used cloud storage. Cloud storage is another storage option, in which the actual online storage media used is transparent to the user. Each storage have their own capacity. Capacity is the number of bytes a storage medium can hold. For example, Gigabyte(GB). the approximate number of GB is 1 trillion. Items on a storage medium remain intact even when you turn off a computer or mobile device. Access time measures the amount of time it takes a storage device to locate an item on a storage medium and the time required to deliver an item from memory to the processor.  

Hard Disks

A hard disk contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information. Characteristic of hard disk comprised bezel, sealed chamber, disk platter, head arm, head actuator, drive electronic PCB, head electronic, antivibration mount, read/write head and mounting chassis. A head crash occurs when a read/write head touches the surface of a platter. We have must remember to keep a backup of our hard disk. Besides that, an external hard disk is a separate freestanding storage device that connects with a cable to a USB port or other port on a computer or mobile device.

Flash Memory Storage

Flash memory chips are a type of solid state media and contain no moving parts. There are two type of flash memory storage. A SSD(solid state drive) and HDD. The differences between these two are prices, capacity, lifespan, power consumption and speed. Both have their own advantages and disadvantages. A memory card is a removable flash memory device that you insert and remove from a slot in a computer, mobile device, or card reader/writer. USB flash drives plug into a USB port on a computer or mobile device.

Cloud Storage

Cloud storage is an Internet service that provides storage to computer or mobile device users. Its need an internet access to get the data that we had save in the storage. It is really compatible because we can access our data wherever we are.

Optical Disks

An optical disc consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser. When we put the CD in their socket at our computer, how a laser reads the data on an Optical Disks ? first, a laser diode shines a light beam toward the disc. Second, if light strikes a pit, it scatters, and if light strikes a land, it is reflected back toward the laser diode. Thirdly, reflected light is deflected to a light-sensing diode. Absence of reflected light is read as a digital signal of 0. Optical discs commonly store items in a single track that spirals from the center of the disc to the edge of the disc. Track is divided into evenly sized sectors. There are several type of Optical Disk. A CD-ROM, a CD-R and a CD-RW. In addition, DVD-ROM, DVD-R or DVD+R, DVD-RW, DVD+RW and DVD-RAM.

Type of storage