A record that denotes the beginning of a series of records and describes the contents of the records that follow. For example, the International Financial Statistics has a header record which describes a time series and the header record is followed by a number of records which contain the actual time series. Header records are often used when the number of physical records needed to contain the data for a particular variable is not constant for all variables. For instance, in economic time series data files one variable might be a time series that contain 20 years of data and fill 20 physical records while the next variable might contain a time series with only 5 years of data and fill only 5 physical records. The use of a file format that includes header records enables one to determine where the series begin and end. heterogeneous network
