PSPP works with data organized into datasets. A dataset consists of a set of variables, which taken together are said to form a dictionary, and one or more cases, each of which has one value for each variable.
At any given time PSPP has exactly one distinguished dataset, called
the active dataset. Most PSPP commands work only with the
active dataset. In addition to the active dataset, PSPP also supports
any number of additional open datasets. The DATASET commands
can choose a new active dataset from among those that are open, as
well as create and destroy datasets (see DATASET commands).
The sections below describe variables in more detail.