The most useful feature.
WHAT THEY DO
Group records and summarise them without writing formulas.
WHAT THEY ANSWER
Sales by month Revenue by product Profit by customer Enquiries by source Anything grouped by anything
WHY THEY MATTER
They turn a list of transactions into answers, in seconds.
WHAT THEY REQUIRE
Clean data: one row per record, consistent categories, no blanks in key columns.
HOW TO USE ONE
Select the data Insert the summary Choose what to group by and what to total
WHAT TO TRY FIRST
Revenue by month Revenue by product Revenue by customer
Those three answer most basic questions.
WHAT TO ADD
A second grouping, to cross-analyse: product by month, source by outcome.
WHAT TO CHECK
That the total matches your known total.
If not, the data has a problem.
WHAT TO LEARN FIRST
This feature, before any other.