What term describes the length in bytes of each record in a data set?

The term that describes the length in bytes of each record in a data set is "Record size." This term specifically refers to the total number of bytes that a single record occupies, which can include all the fields contained within that record. Understanding record size is critical in database management and data processing as it impacts how data is structured, stored, retrieved, and managed efficiently.

The other options, while related to aspects of data and storage, do not accurately define the length of a record:

Field width refers to the size of individual fields within a record rather than the entire record itself. Data storage record length could be a descriptive term, but it is not the standard terminology used in data management contexts. Memory allocation pertains to how computer memory (RAM) is assigned for various tasks, which does not directly correlate to the concept of record size in a data set.