What is the difference between file and record in OS's view?

Answer 1

These days, on Win32 and *nix at least, there is no difference. A file is just a bag of bytes to the OS, and it's left up to applications to manage and work with those bytes, either all at once or one record at a time.

The days of defining record formats and i/o sources in JCL are long gone.

Answer 2

The Good answer is that 1 ""A collection of related fields treated as a single unit is called a record. A collection of related record treated as a single unit is called a file or a data set""