The EDCS supports the encoding and communication of qualitative and quantitative information associated with physical environments, both real and virtual. This is accomplished by specifying a collection of nine EDCS Dictionaries of environmental concepts. An EDCS Dictionary is a list of EDCS Dictionary Entries each of which specifies a single concept. Each EDCS Dictionary contains entries of a similar nature, however each entry is unique. Each EDCS Dictionary Entry consists of the following fields:

• definition,
• label,
• code,
• references and reference type,
• supplemental references, and
• other EDCS Dictionary-dependent information such as value types, unit symbols, or unit equivalence classes.

The nine EDCS Dictionaries are:

• EDCS Classification (EC) Dictionary,
• EDCS Attribute (EA) Dictionary,
• EDCS Attribute Value Characteristic (EV) Dictionary,
• EDCS Attribute Enumerant (EE) Dictionary,
• EDCS Unit (EU) Dictionary,
• EDCS Unit Scale (ES) Dictionary,
• EDCS Unit Equivalence Class (EQ) Dictionary,
• EDCS Organizational Schema (EO) Dictionary, and
• EDCS Group (EG) Dictionary.

Additional entries may be added to most EDCS Dictionaries through the process of registration.

The EDCS Application Program Interface (API) supports conversion between real values given in different units of measure.