Record can be seen as a line of data file or as a row of a database table. The record consists of fields. Each field can have different data type. See Data Types in Metadata.
Each record is of one of the following three types:
In a delimited record, every two adjacent fields are separated from each other by a delimiter and the whole record is terminated by record delimiter as well.
In a fixed record each field has some specified length (size). The length is counted in number of characters.
In a mixed record each field can be separated from each other by a delimiter and also have some specified length (size). The size is counted in number of characters.
This record type is a mixture of both types above. Each individual field may have different properties. Some fields may only have a delimiter, others may have specified size, the rest of them may have both delimiter and size.