In computer science, a record-oriented filesystem is a file system where data is stored as collections of records. This is in contrast to a byte-oriented filesystem, where the data is treated as an unformatted stream of bytes. There are several different possible record formats; the details vary depending on the particular system. In general the formats can be fixed-length or variable length, with different physical organizations or padding mechanisms; metadata may be associated with the file records to define the record length, or the data may be part of the record. Different access methods for records may be provided, for example records may be retrieved in sequential order, by key, or by record number. Origin and characteristics Record-oriented filesystems are frequently associated with mainframe operating systems, such as OS/360 and successors and DOS/360 and successors, and midrange operating systems, such as RSX-11 and VMS. However, they originated earlier in software such as Input/Output Control System (IOCS). Record-oriented filesystems can be supported on media other than direct access devices. A deck of punched cards can be considered a record-oriented file. A magnetic tape is an example of a medium that can support records of uniform length or variable length. In a record file system, a programmer designs the records that may be used in a file. All application programs accessing the file, whether adding, reading, or updating records share an understanding of the design of the records. In DOS/360, OS/360, and their successors there is no restriction on the bit patterns composing the data record, i.e. there is no delimiter character; this is not always true in other software, e.g., certain record types for RCA File Control Processor (FCP) on the 301, 501, 601 and 3301. The file comes into existence when a file create request is issued to the filesystem. Some information about the file may be included with the create request. This information may specify that the file has fixed-length records (all records are the same size) along with the size of the records. Alternatively, the specification may state that the records are of variable length, along with the maximum record length. Additional information including blocking factor, binary vs. text and the maximum number of records may be specified. It may be permitted to read only the beginning of a record; the next sequential read returns the next collection of data (record) that the writer intended to be grouped