so used for a set of
logical abstractions employed in constructing such a model. [Computer and Information Sciences] 
n., The representation of information according to preset specifications (e.g., plaintext files, HTML, TIFF, etc.). [Computer and Information Sciences] 
relationships between different types of elements and sometimes by characterizing the things to which the elements refer.
n., A collection of data items and links between them, structured in a way that allows it to be accessed, manipulated a