8.1 Introduction and notation 9In an external sort there are so many records to be sorted that they must be kept in external les on disks, tapes, or the like. In an internal sort the records can all be kept internally in high-speed memory. We consider only internal sorting. We use the notation and classes set up in Chapters 6 and 7. thus we shall sort lists of records into the order determined by keys associated with the records. The declarations for a list and the names assigned to various types and operations will be the same as in previous chapters.8.1 Introduction and notation ◆In an external sort, there are so many records to be sorted that they must be kept in external les on disks, tapes, or the like. In an internal sort the records can all be kept internally in high-speed memory. We consider only internal sorting. ◆We use the notation and classes set up in Chapters 6 and 7. Thus we shall sort lists of records into the order determined by keys associated with the records. The declarations for a list and the names assigned to various types and operations will be the same as in previous chapters