All information is kept (or “saved”) in the form of computer files. Files can contain different types of data: text, images, sounds, video, etc.. Depending on the type of data they contain, files can also be of several types: documents (text, possibly supplemented by tables, graphs, images, etc.), images, audio, video etc.
For a better organization of the files on the disk, they are structured like a traditional archives in “folders” or “directories”.
Any file is stored in a folder or directory. Most disks have many folders, all of which may contain files. (1)
A folder can contain (in addition to files) and other folders (these are often referred to as sub-folders, and folder where are retained as parent folder), and these in turn can contain other sub-folders, leading to many levels. Main folder, found at the top of this pyramid, is called the “root”.
Users can create, move and delete folders as needed. Most documents created in Windows are stored in the folder “My Documents ” and its sub-folders. Good organization of files and folders, their structure, is very important for those working with multiple documents.
These files and folders are stored on storage devices (in most cases “disks”). Usually the user keeps files on computer’s “hard disk drive”, but they can be stored also on “floppy disks”, CD, DVD, etc.
Of particular importance in the choice of storage devices has their capacity (the amount of information it can store).
The amount of information is measured in “byte” (plural “bytes”) (2) – this corresponds roughly to a text character (a letter, number, punctuation mark, etc.). Multiple byte are described in the table below:
|Name||Abbreviation||Approximate size* (bytes)|
* Note: Dimensions are approximate because computers work with powers of 2, so that a kilobyte is actually 1,024 bytes, and a megabyte is 1024 x 1024 bytes (3), etc.
The most common storage devices:
- Diskette (floppy disk) – often used to preserve and transfer small amounts of data.
- CD (compact disc) – to replace the disk due to higher storage capacity (see table). At present, the major part of the software is distributed on a CD.
- DVD (Digital Video Device) – similar to the CD, but with a larger storage capacity.
- Hard drive – this is the main storage device for modern computers. Hard drives have a higher storage capacity devices mentioned above, but most are fixed inside the computer, not allowing transportation datelor (4).
- Memory flash (5)
|Storage device type||Amount of information stored||Corresponding approximately|
|Diskette||1.44 MB||720 pages A4|
|CD||650 MB||A small library|
|DVD||4.5 GB||A feature length film|
|Hard-disk||100GB||Over 20 films|
In addition to the devices mentioned above there are many other new standards are continuously developed .
1) The terms “folder” and ” directory” are equivalent – the term folder is used mostly for Windows, unlike the “director” – used mainly in older operating systems
2) A byte is in turn made up of 8 bits. Bit is the basic unit of measurement of the amount of information; however, due to the large quantities that are commonly circulated, it is rarely used .
3) 1 byte = 8 bits = 23 bits.
4) There are also portable hard drives
5) They can be written and read faster than other media, but for older operating systems may experience problems in accessing .