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TOPIC 3.4: OPTICAL DISC AND DRIVES TOPIC 3.5: CLOUD STORAGE - Coggle…
TOPIC 3.4: OPTICAL DISC
AND DRIVES
TOPIC 3.5: CLOUD STORAGE
Descriptions
Also called compact disks or laser optical disks, used laser technology to store data at densities many times greater than those of magnetic disks.
The most common optical disk system used with PCs called CD-ROM (compact disk read only memory).
CD-ROM is read-only storage.
Today's optical disks can hold over 100 GB of data - million of typewritten pages or medium-sized library all on single disc.
A laser beam alters the surface of a plastic or metallic disc to represent data.
The disc is read by an optical disc drive using a laser that projects a tiny beam of light on these areas.
Descriptions (...cont.)
An optical disc consists of a flat, round, portable disc made of metal, plastic and lacquer that is written and read by a laser.
Typically store software, data, digital photos, movies and music.
Read only vs. rewritable.
How Laser Read Data on Optical Disc
Step 1:
A laser diode shines a light beam toward the disc.
Step 2:
If light strikes a pit, it scatters. If light strikes a land, it is reflected back toward the laser diode.
Step 3:
Reflected light is deflected to a light-sensing diode, which sends a digital signal of 1 to the computer. Absence of reflected light is read as a digital signal of 0.
Descriptions
...an Internet service that provides storage to computer users.
...responsible for keeping the data available and accessible, and the physical environment protected and running.
People and organizations buy or lease storage capacity from the providers to store user, organization or application data.
List of Cloud Storage Provider
sync.com
pCloud
Microsoft Azure
MEGA
SME
Amazon S3
tresorit
OneDrive
Google Cloud
Dropbox
Google Drive
Pros and Cons of Cloud Storage
Pros
Lower cost
Easier management
Enables sharing and access from anywhere
Cons
Loss of control
No guarantees of data availability
Provider failures