The type attribute on a graph element determines the initial mode of a graph view. Possible values are bar, line, and chart, but bar is the default. The graph view is highly interactive, so the user can switch between the different modes and also add and remove fields. Pivot views have their own root element, pivot.

The field elements tell Odoo what to display on which axis. For all graph modes, you need at least one field with the row type and one with the measure type to see anything useful. Fields of the row type determine the grouping, while those of the measure type stand for the value(s) to be shown. Line graphs only support one field of each type, while charts and bars handle two group fields with one measure nicely. The pivot view supports an arbitrary amount of group and measure fields. Nothing will break if you switch to a mode that doesn't support the amount of groups and measures you defined; some fields will just be ignored and the result might not be as interesting as it could be.