Total: above the table is the number of packages listed. Each line shows the SERVICE NAME (the service class the package is filed under), the PACKAGE NAME, the PART AMOUNT charged for parts on that package across all the invoices in the range, the LABOR AMOUNT charged for its labor lines, the COG FROM INVENTORY (cost of goods: the purchase cost of each part multiplied by the quantity sold), the GROSS PROFIT (part amount plus labor amount, less cost of goods) and the GROSS PROFIT %, which is the gross profit divided by the part and labor amount together. The percentage turns orange when it falls below 70 and red when it falls below 50, so a package that needs a price review stands out. Only finalized invoices count; drafts, voided and deleted invoices are left out. The foot row repeats the headings and sums the part, labor, cost of goods and gross profit columns, with the overall gross profit percentage for the range.
The Add To Favorites switch beside the heading saves the report under Favorites on the Reports page. Which reports you see depends on your admin group permissions.