Here is a pretty good description on a Record-oriented filesystem:
In computer science, a record-oriented filesystem is a file system
where files are stored as collections of records. There are several
different 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 methods to access
records may be provided, for example sequential, by key or by record
number.
Here is a pretty good description on a Record-oriented filesystem: