> What is it storage storing if not data or files?
Objects. Cloud Storage is the S3 competitor.
> Why are files not data?
“Data” as in rows in a database. Like Dynamo.
Everything on a computer is data. The thing you’ve got to understand is that the terms we use, “objects”, “files”, “data” — these don’t refer to types of data, but rather to access paradigms for data. The semantics of their storage, indexing, mutability, etc.
An object is a blob of data named by a key, that you can retrieve entirely, or overwrite entirely, and where usually you automatically get a version history of old versions that have been overwritten that you can retrieve, with a cutoff for automatic GC.
“Data” is a structured tuple that a database knows how to index into, and sort by the columns of. You insert rows, update columns of rows by a key, or delete rows by a key.
“Files” are seekable streams where you can index anywhere into a file by position and then read(2) or write(2) data at that position, and where other clients can see those updates as soon as you sync(2), without needing to close(2) the file first.
All could be used to implement the other (S3 is implemented in terms of Dynamo rows holding chunks of object data, for example.) But each access semantics has use-cases for which it is an impedance match or mismatch.