External data representation and marshalling.
External data representation and marshalling. In a computer programming language, you may refer to data that is stored in data structures using the language’s internal syntax. For instance, you might have objects like: “linked list” or “hash map” or “binary tree” or “string”. or “integer”. or “set”. Outside of a computer program you have things like: filesystem, file. Now the file format is independent of whatever your favorite programming language is. Most files are just a big bunch of bytes or characters or whatnot and you can’t tell what’s in them without extra information (like a filename extension or the first few bytes of the file might be magic). But in general you can come up with way more ways to represent data in a computer program than you can in a file on disk. So if you want to move information back and forth between your computer program and pretty much anywhere outside of your computer program (like a disk or a network packet)...
