A serial file is one in which the records have been stored in the order in which they have occurred. They have not been sorted into any particular order.

An example of a serial file is an unsorted transaction file.

A shopping list is an example of a non-computerised serial file. Items are appended to the list when that item runs low.

Serial files can be stored on tape, disc or in memory.

A sequential file is one in which the records are stored in sorted order of one or more key fields.

An example of a sequential file is a sorted transaction file.

A class register is an example of a non-computerised sequential file sorted on surname.