Quote: --- Original message by: Bungie
A tag is the fundamental unit of our resource system. It corresponds to a single file on disk and a C structure in memory. Our tag system is similar to XML; where XML defines data as an XML file and its definition as a schema, we define data as a tag and its definition as a tag_group. However, there are two main differences: XML is stored as text while a tag is a stored as binary data, and an XML schema is defined in a text file while a tag_group is defined in code. We define tag_groups in code using a set of preprocessor macros that break down the corresponding C structure into its component types, e.g. integers, floats, strings.