Transfer of data [data: information without context, eg a list of students with numbers beside their names is data, when it's made clear that those numbers represent their placing in a 100 metre race, the data becomes information ] files containing pictures (graphics), text, sound, or numbers is possible from one computer to another, one make of hardware [hardware: the physical components of a computer ] to another, and one application to another. This is possible because standard file types and data formats have been developed.
Data does not need to be transfered on physical media [media: The plural form of medium - examples include paint, clay, glass, textiles, photography, print and so on. Wet media includes paints and pens. Dry media includes pencils and charcoals. ], it can be transmitted at rapid speeds around the globe.
Data files are stored in a number of formats, the formats depend on which application [application: applications serve a specific purpose, eg Microsoft Word is used for word processing ] created the file to begin with. For example, Microsoft Word stores files as *.doc but Adobe Photoshop stores files in a different format - *.psd. The file extension identifies the file's format.
When data is transferred from one computer to another, the computer receiving the data file may not be able to read the format without the right application installed. For example, an image created in Adobe Photoshop and saved as a *.psd file (Photoshop's format) would not be readable by Microsoft Paint.
This is becoming less of a problem as standardisation matures and applications expand the list of file types they're able to read.