It's like[1] serializing program state to a sequential form (eg xml, json, protocol buffer, etc). The sequential form is useful for communication and persisten

It's like[1] serializing program state to a sequential form (eg xml, json, protocol buffer, etc). The sequential form is useful for communication and persistent storage. While the sequential form can be used for processing, it's clunky, because not its main usage. Consider XSLT. The set of valid messages is even formally called a language. [1] Or, rather, serialization is like it.