These are the different kinds of ASCII data returned by a fully-equipped DODS server. ("Fully equipped" implies that the server has, on its execution path, all the supported DODS service programs.)
The DODS Data Descriptor Structure is a description of the data
contained in the dataset. It contains information about the data
types and names represented in the dataset. Programmers can think
of the DDS as containing the type declarations for the data. The
DDS is fully described in The OPeNDAP User Guide. The DDS is created with a
service program called *_dds, where the * is the same
two-letter abbreviation used in the server name (nph-*).
The DODS Data Attribute Structure contains information about
the data in the dataset--the metadata. It is a hierarchical list
of name-type-value triples, where the names of the containers
correspond to entries in the DDS. The DAS is fully described in
The OPeNDAP User Guide. The DAS is created with a service program called
*_das, where the * is the same two-letter abbreviation
used in the server name (nph-*).
If a DODS server is equipped with a service program called
asciival, it can convert binary data to ascii data on the fly,
allowing you to use a standard web browser (such as Netscape) to
examine data. This feature can also be used to import data into a
client that may not be able to process DODS data encoded in the
standard binary format.