Formally, a data model has three parts (according to the Internet Engineering Task Force):

1. A collection of data objects such as lists, tables, relations, ...
2. A collection of operations that can be applied to the objects such as retrieval, update, subsetting, averaging, ...
3. A collection of integrity rules that define the legal states (set of values) or changes of state (operations on values)

We will not be that formal. We will use simple Unified Modeling Language (UML) pictures

• to describe what netCDF data objects are and what you can do with them
• to talk at a conceptual level, above the data format layer and independent of particular programming language APIs

2007 Unidata NetCDF Workshop for Developers and Data Providers > The "Classic" NetCDF Data Model