How parts of a graph are represented – PB Docs 2017

Graphs consist of parts: a title, a legend, and axes. Each of
these parts has a set of display properties. These display properties
are themselves stored as properties in a subobject (structure) of Graph
called grDispAttr.

For example, graphs have a Title property, which specifies the
text for the title. Graphs also have a property TitleDispAttr, of type
grDispAttr, which itself contains properties that specify all the
characteristics of the title text, such as the font, size, whether the
text is italicized, and so on.

Similarly, graphs have axes, each of which also has a set of
properties. These properties are stored in a subobject (structure) of
Graph called grAxis. For example, graphs have a property Values, of type
grAxis, which specifies the properties of the Value axis, such as
whether to use autoscaling of values, the number of major and minor
divisions, the axis label, and so on.

Here is a representation of the properties of a graph: