AS IT Chapter 10 - File and Data Management

.txt

Text File.

Stores plain text without any formatting. It is useful for transferring data between applications but any formatting is lost

.csv

Comma Separated Values.

Stores structured data as plain text in rows with each column separated by commas. It is useful for transferring data between databases and spreadsheets and other applications that require data in a structured format.

.rtf

Rich Text Format.

Stores text based documents and includes the formatting (rich text). It is used to transfer data between different word processing or other text based applications

.docx

Microsoft Word XML (Extensible Markup Language).

Stores Microsofts word processing documents in open XML format by saving all objects separately within a compressed file.

.pdf

Portable Document Format.

Used to share read only documents in a common format that can be accessed by any PDF reader software. It is commonly used for storing documents on the web as its contents can be indexed by search engines.

.odt

OpenDocumet Text.

An open -source file type for word processor documents that is used by open source word processors and is not tied to one manufacturer

.ods

OpenDocument Spreadsheet.

An open source file type for spreadsheets that is used by open source spreadsheet software and is not tied to one manufacturer

.odp

OpenDocument Presentation.

Open source file type for presentations that is used by open source presentation software and is not tied to one manufacturer

.html

Hypertext Markup Language.

Stores webpages that can be opened by any web browser.

.xml

Extensible Markup Language.

A data file that uses markup language to define objects and their attributes. They are used to transfer data between applications and can be read by a simple text editor

.avi

Audio Video Interleave (video file)

Microsofts method of storing video files with very little compression. File sizes are very big but no data is lost

.mp4

Moving Pictures Experts Group (MPEG) Layer 4 (video -file).

Audio and video are compressed and videos can be shared across the internet

.wav

Waveform Audio File Format.

Stores audio files as waveform data and enables different sampling rates and bit rates. This is the standard format for audio CDs but does not include compression so files are large

.mp3

MPEG layer 3 audio compression.

Stores audio files in a compressed format approximately 10% the size of .wav files. Enables audio files to be shared across the internet

.bmp

Bitmap Image.

Stores images as uncompressed raster images, storing each pixel individually. They are large files but can be accessed by any software

.jpg

Joint Photographic Experts Group (compressed image)

Stores images as compressed rater images. It is used by most digital cameras and is a common format for web graphics but its use of lossy compression can mean some quality is lost

.png

Portable Network Graphic

Stores images as compressed raster images and can include background transparency making it useful when images are required on different colour backgrounds.

.svg

Scalable Vector Graphics

Stores images as two-dimensional (2D) Vector graphics. It is a standard format for using vector graphics on the web

.exe

Executable Program File

Stores program object code which enables the program to be executed by the computer.

Proprietary File Formats Definition

File formats that are owned by someone and are developed by software manufacturers for use with their software. e.g. .docx file format for microsoft

Proprietary file formats Advantages (2)

* Allow software to store data in the most suitable way for that program or feature

* Allows software developers to provide new features, that would not otherwise be included

Proprietary File Formats Disadvantages (2)

* It is rare that the file will open using other manufacturers software, meaning you can only use the program you used to open them.

* Makes sharing files difficult

Open - source file formats

File types designed for use by any proprietary software or open source software. e.g. JPG, PNG, ePub, XML, MPEG.

Open - source file formats Advantages (4)

* Free from copyright, patents and trademarks

* Their structure is known publicly

* Maintained by an international standards organisation or a public interest group

MAIN * The files can be shared between users of different software

Open -Source File Formats Disadvantages (1)

Can slow development of new features in open source software because new features will require the file format standard to be updated.

ePub

e-books that imitate printed books, contain text and graphics and sometimes give the reader the option of making notes, look up words, turn pages, etc.

MPEG

Compressed Video

Generic File Formats

When data is transferred between software, the data is exported from the software into a generic file format and these can be imported into software.

Store essential data but do not include any formatting

Main generic file formats used with databases

csv and txt

Indexed Sequential Access Definition