Cloud Storage And Optical Disks

Cloud StorageAnd

Optical DisksBy:

Sayam Asjad

Cloud Storage• Cloud Storage is an internet service that provides hard

disk storage to computer users.• Types of services provided by service providers vary.

Figure shows variety of cloud storage providers.

Some of the more widely used cloud storage providers

Fee Arrangements

• Policies regarding fee arrangements vary.• For example, one cloud storage service provides 25 GB of

storage free to registered users.• Another charges $5 per month for 150 GB of storage.• For enterprises, cloud storage services typically charge for

storage on a per gigabyte basis, such as 15 cents per gigabyte

Reason to subscribe ?

• To access files on the Internet from any computer or device that has Internet access.

• To allow others to access their files on the Internet so that others can listen to an audio file, watch a video clip, or view a photo — instead of e-mailing the file to them.

• To view time-critical data and images immediately while away from the main office or location. For example, you can view important if you are away from home or office.

• To store offsite backups of data.• To provide data center functions, relieving enterprises of this

task

Optical disks• An Optical disc is type of optical storage media that consists of

a flat, round, portable disc made of metal, plastic, and lacquer.

Optical Disc Drive in PC

• Optical Disc may be one/double sided.

• Light scribe technology.• Optical Discs store items in form

of microscopic pits and lands.• A high-powered laser light

creates the pits.• A lower power laser reads items

and the reflected light is converted into bits.

• Manufacturers claim that a properly cared for high-quality optical

disc will last 5 years but could last up to 100 years.

Some guidelines for the proper care of optical discs

Formats of Optical disks

• Figure describes a variety of optical disc formats and specifies whether a user can read from the disc, write to the disc, and/or erase the disc

• It also characteristics unique to each of these disc formats

CDs• A CD-ROM, or compact disc read-only memory, is a type of

optical disc that users can read but not write (record) or erase — hence, the name read-only.

• A standard CD-ROM is called a single-session disc because manufacturers write all items on the disc at one time.

• A typical CD-ROM holds from 650 MB to 1 GB.• CD-Rs and CD-RWs allow users to write data with CW-R and CD-

RW drive. The Process of writing on a optical disc is called burning.

• A CD-R(compact disc-recordable) is a multisession optical disc on which users can write, but not erase their items such as text, audio, videos etc.

• A CD-RW(compact disc-rewritable) is an erasable multisession disc you can write on multiple times.

• The process of copying audio and/or video data from a purchased disc and saving it on digital media is called Ripping.

Archive Discs and Picture CDs

• You can save shared photos on a archive disc from a photo sharing community, which stores in jpg file format.

• A Kodak Picture CD stores digital versions of film using a jpg file format.

DVDs and Blu-ray Discs• A DVD-ROM is a high-capacity optical disc on which users can

read but not write or erase.

• DVD-ROM uses three storage techniques.

• The first involves making the disc denser by packing the pits closer together.

• The second involves using two layers of pits. lower layer of pits is semitransparent so that it can through it to the upper part. This technique doubles the capacity of the disc.

• Finally, some DVD-ROMs are double-sided.

• A Blu-ray Disk (BD) is a format which has storage capacities of 100 GB

storage capacities of DVD and Blu-ray media

• HD VMD• UMD.• A mini-DVD• The mini Blu-ray

Disc

• DVD-R, DVD+R and BD-R allow users to write on the disc once and read (play) it many times.

• DVD-RW, DVD+RW, and DVD+RAM are rewritable DVD formats.

• BD-RE is a high-capacity rewritable DVD format.• To write on these discs, you must have a compatible drive or

recorder.

Recordable and Rewritable DVDs