Workbench Command is a set of command-line tools that can be used to perform simple and complex operations within Connectome Workbench.
The GIFTI format is an established data file format intended for use with
surface-based data. It has subtypes for geometry (.surf.gii), continuous
data (.func.gii, .shape.gii), and integer label data (.label.gii). The
files that contain data, rather than geometry, consist mainly of a 2D array,
with one dimension having length equal to the number of vertices in the
surface. Label files (.label.gii) also contain a list of integer values
that are used in the file, plus a name and a color for each one. In
workbench, the files for continuous data are called 'metric files', and
.func.gii is usually the preferred extension, but there is no difference in
file format between .func.gii and .shape.gii. Geometry files are simply
called 'surface files', and must contain only the coordinate and triangle
arrays. Notably, other software may put data arrays (the equivalent of a
metric file) into the same file as the geometry information. Workbench does
not support this kind of combined format, and you must use other tools to
separate the data array from the geometry.
For the full details of the GIFTI format, see
http://www.nitrc.org/projects/gifti/