Chapter 1.  Introduction

This is an adaptation of a tutorial that was originally meant for OPeNDAP, but was later refocused on SNCTOOLS as the way to access both OPeNDAP and local netCDF files. SNCTOOLS can use either MATLAB's native netcdf package or mexnc as a way to read and write local netcdf files, but can also read OPeNDAP datasets.

The OPeNDAP website defines itself as

OPeNDAP provides software which makes local data accessible to remote locations regardless of local storage format. OPeNDAP also provides tools for transforming existing applications into OPeNDAP clients (i.e., enabling them to remotely access OPeNDAP served data).

So, you can basically think of it as a way to access remotely-stored datasets from your matlab session.