Wiley 978-0-470-76902-7 Datový list stáhnout pdf (Strana 11)

Laptops store data on an internal hard drive —

a spinning hard disk inside the laptop — via

magnetic recording. An arm with a magnetic

head moves over the disk to read or write data

on the disk as it spins. Data can also be erased,

although the magnetic data pattern may remain

on the drive after you have erased it.

Most laptops also have a disc drive. Depending

on the type of drive, you can insert a CD, DVD,

and/or Blu-ray disc into it to store data on the

disc. Other data-storage options include Flash

drives and portable external hard drives.

Understand Drives

and Data Storage

How Data Is Stored

Data is stored in files as a series of bytes in a sector on your hard drive. Each sector on the drive can

contain a certain number of bytes. When you access data, whether by opening a piece of software or

opening a file, the read/write heads move across the hard drive, looking for the required bytes. These

bytes may be located in various sectors of the drive. Because bytes in files are spread across multiple

sectors, those files are said to be fragmented; fragmented files take longer to load than files whose bytes

are stored in a single segment.

Partitions

You can create partitions on a hard drive that essentially break it up into two or more hard drives. You

may do this to run different operating systems on the same computer. You may also create a partition to

foster the appearance of having multiple hard drives for file-management purposes or to accommodate

multiple users. Creating additional partitions also enables you to separate your data from your operating

system; that way, in the event your operating system is damaged, your data remains safe. To partition a

hard drive in Windows 7, there must be either unallocated disk space or free space on the hard drive.

Using the Disc Drive

As mentioned, most laptops include a disc drive, into which you can insert

various storage media. These storage media include compact discs (CDs), digital

versatile discs (DVDs), and Blu-ray discs. Depending on your disc drive’s setup,

you may be able to read data on and write data to all three of these types of

storage media.

Storing Data on CD

Nearly all disc drives support the use of compact discs, or CDs — hard plastic

disks on which you can store data, music, or images. CDs can typically store up

to 700MB of data. To read from or write to a CD, your laptop must have a CD

drive with the appropriate support (read, write, or read/write).

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Wiley 978-0-470-76902-7 Datový list Strana 11