关于数据模型与数据格式的区别

I recently had to explain to an audience what is the difference between a data model and a data format. They wanted to explain why we just don't use xml to do the basic thing we do with RDF. Although i could explain a bunch of things, such as a distributed data model, reasoning and etc.. I was somewhat enable to explain the difference between a data model and a data format.I recently had to explain to an audience what i