Final answer:
The -/+ buttons in a PivotTable are used to expand and collapse sections of data, providing a detailed or summary view depending on your preference.
Step-by-step explanation:
The purpose of the -/+ buttons that appear across the categories in a PivotTable is to expand and collapse sections of data. This feature allows you to view detailed information or a summary by showing or hiding the underlying data. When you click the '+' button, it expands the section to show more detailed rows or columns within that category. Conversely, clicking the '-' button collapses the section, hiding those details and providing a summary view. These buttons do not add or remove items, sort data, or filter options within the PivotTable.