There are two CDF formats: multi-file and single-file. The choice of which format to use will depend on how the CDF is to be accessed. Note that the CDFconvert toolkit program can be used to change the format of an existing CDF (creating a new CDF with the desired format).
The default format for a created CDF was determined when your CDF distribution was built and installed. Consult your system manager for this default. In a user application, the Internal Interface must be used to change the format of a CDF. The format of an existing CDF can be changed only if no variables have been created in the CDF. If the SkeletonCDF toolkit program is used to create a CDF, the format is specified in the skeleton table (see Section 3.8).
A CDF's format is changed by using the <PUT_,CDF_FORMAT_> operation of the Internal Interface.