Wide format stores data across many columns, while long format organizes data into key-value rows.
Try it with AIWide format features unique variables in separate columns, making it readable for human reporting. Long format, or 'tidy' data, places all values in a single column with a corresponding identifier column, which is the preferred structure for PivotTables and Power Query.
Wide: Columns for 'Jan Sales', 'Feb Sales'. Long: One column for 'Month' and one for 'Sales Amount'.
Long format is required for most Excel analytical tools like PivotTables, as it allows for easier filtering, grouping, and aggregation.