Intel® Fortran Compiler 17.0 Developer Guide and Reference
Files may be composed of records. Each record is one entry in the file. A record can be a line from a terminal or a logical record on a magnetic tape or disk file. All records within one file are of the same type.
In Fortran, the number of bytes transferred to a record must be less than or equal to the record length. One record is transferred for each unformatted READ or WRITE statement. A formatted READ or WRITE statement can transfer more than one record using the slash (/) edit descriptor.
For binary files, a single READ or WRITE statement reads or writes as many records as needed to accommodate the number of bytes being transferred. On output, incomplete formatted records are padded with spaces. Incomplete unformatted and binary records are padded with undefined bytes (zeros).