What is "filing-cabinet"
A (Brazilian Portuguese) or (European Portuguese) computer file is a resource for storing information, which is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available to programs for use after the running program has been completed. Computer files can be considered as the modern equivalent of paper documents that are traditionally stored in office and library archives, this being the origin of the term.
Storage drives, for example hard drives, have complex implementation details, the file hides these details so that the user can manipulate the information in a simpler way. A file can be considered as an object, having a name that identifies it, attributes and values.
Files may contain structured or unstructured data. Unstructured files have a byte sequence, while structured files can be organized into records or tree (data structure). The implementation of the file system, including the file format, is the responsibility of the operating system, that is, each file depends on the decision of the OS designer.
Some operating systems like UNIX do not care about file extension or its internal structure3, simply treating each file as a sequence of unstructured bytes, leaving the responsibility of interpreting its meaning to the program that opened it.