File Formats (Cambridge International IGCSE ICT)

Spec point — 11.1.2

File formats

What are file formats?

• File formats are the file types used to store the data in a file
• File formats define the structure and organisation of the data in a file and determine which software can be used to read the contents of the file
• There are a variety of file formats used, depending on the type of file being used

Generic File Formats

• Generic file formats are file types that are compatible and allow sharing between different devices and software programs

• Non-generic files are types that require special software or hardware to be accessed

• Generic file types are needed for the following reasons:

  • Allowing the exchange of data across different types of applications
  • They are widely adopted and therefore can be accessed by many users or devices
  • Generic files can be created, edited and accessed across many different devices

Characteristics & Uses of File Formats

Generic Images Files

• Joint Photographic Expert Group (.jpg)

  • JPEG is a widely used image file format which uses the lossy compression method
  • Significantly reduces file size while maintaining acceptable image quality
  • JPEG files are commonly used for storing and transmitting digital photographs

• Portable Network Graphic (.png)

  • PNG uses lossless compression

  • PNGs preserve high-quality images whilst still providing small file sizes

  • Its transparency support allows its graphics to be placed into different backgrounds easily

  • They are commonly used for:

    • web design
    • digital illustrations
    • logos
    • icons

• Graphics Interchange Format (.gif)

  • Used for short, animated images and simple graphics
  • Use a lossless compression algorithm
  • Maintain high image quality while keeping file sizes small
  • Used in online platforms, including social media, messaging apps, and websites

Generic Video Files

• Moving pictures expert group layer 4 (.mp4)

  • A multimedia container rather than a single file format
  • Can be used for video, image, and audio types
  • Uses advanced compression techniques to achieve high-quality video playback
  • The compression algorithm keeps file sizes relatively small
  • Popular for streaming and transferring videos online

• Quicktime Movie (.mov)

  • A multimedia container format developed by Apple

  • Used for storing video, audio, and other media data

  • Can maintain excellent image quality while retaining smaller file sizes

  • Suitable for online streaming and local playback

  • Widely used in:

    • professional video editing
    • film production
    • multimedia projects

Generic Audio Files

• Moving pictures expert group layer 3 (.mp3)

  • A popular audio file format known for its high-quality
  • Allows for a significant reduction in file size but minimal differences in sound quality
  • Compatible with a wide range of devices and audio streaming platforms
  • Become the standard format for digital music distribution

• Waveform File Audio format (.wav)

  • Uncompressed audio file format known for its high lossless quality

  • Preserves the original audio waveform.

  • Commonly used in:

    • music industry
    • broadcast
    • multimedia production

Generic Text Files

• Text (.txt)

  • Used for storing plain text data
  • Contains only human-readable text without any additional formatting or styling
  • Extensively supported across different platforms and applications
  • Can be opened and edited using a word processor or basic text editor

• Rich Text Format (.rtf)

  • RTF is a file format used for storing formatted text documents that can contain different text styles, fonts, colours, and other basic formatting elements
  • RTF can be opened and edited using a wide range of text editors and word processors, making them suitable for creating documents that require basic formatting, such as letters, reports, and academic papers

• Comma separated values (.csv)

  • A plain text file format used for storing data in a structured manner
  • Consist of rows and columns, with each cell separated by a comma
  • Widely supported
  • Easy to import and export data between different applications and platforms
  • Commonly used for tasks involving data analysis, database management
  • Can be easily opened and edited using spreadsheet software

• Portable Document Format (.pdf)

  • Widely used file format with its ability to retain the layout and formatting of documents across a range of platforms
  • Documents contain text, images, graphics, and even interactive elements.
  • Can be password-protected to stop unauthorised users from editing
  • Allows users to provide a digital signature feature acting as a digital ‘ink signature’

Generic Compressed Files

• Zip (.zip)

  • A container used for compression
  • Allows multiple files and folders to be compressed into a single, smaller-sized archive
  • Uses lossless compression algorithms to reduce file sizes

• Roshal archive (.rar)

  • A container used for compression
  • Similar to .ZIP, however, it uses a proprietary compression algorithm
  • Generally results in higher compression ratios compared to other formats
  • Commonly used for sharing files over the internet and when space-saving is essential

Generic Web Development & Browsing Files

• Hypertext Markup Language (.html)

  • A global file format used for creating and structuring web pages
  • Contain text-based code that defines the structure, layout, and content of a webpage
  • Rendered by web browsers, allowing users to view and interact with web pages
  • Used across many different devices and platforms

• Cascading Style Sheets (.css)

  • A file format that is attached to an HTML document
  • Used to determine presentation and styling such as colours, fonts, layout, and positioning
  • Is widely used in web development to create responsive and attractive designs

Worked Example A teacher wants to write a document and could save the document as a .txt or an .rtf file format. Explain the difference between .txt and .rtf file formats. [3]

Final answer: Answer

Three from:

RTF has basic formatting (embolden, underline, etc.) while TXT is plain text [1]

RTF is capable of paragraph formatting while TXT is not [1]

RTF is capable of creating bulleted lists while TXT is not [1]

RTF files can include images while TXT cannot [1]

TXT takes up less memory while RTF takes up more memory [1]