ALL means every value in your data set, whether or not it is excluded by your current selections.
All:-sum(all(sales)
So if you have five years of data, and have selected a year, and have a chart showing sum(ALL sales) by month, each month will have the same total, which will be the sum of all sales for the past five years. Note that it is now preferred to use sum({1} sales), which has the same effect.
Total:-sum(total(sales)
Total, on the other hand, does take your current selections into account. But it ignores what row you're on in a table. So back to our example, sum(TOTAL amount) would again have the same total for each month, but it would be the sum of all sales for the selected year.
