COUNT allows you to calculate a total number of selected cells that contain numbers. SUM allows you to calculate a total sum of the selected cells. IF allows you to set the value of a cell depending on whether the given condition is true or not.
The COUNT function has a couple of variations. This includes COUNTIF, which counts the number of cells based on some given condition, such as ">9.". COUNTIFS allows a count based on multiple conditions. SUM has the same variations: SUMIF and SUMIFS.
The IF function takes a condition and two cell values. If the condition is true, Excel assigns the first value to the cell, and if the condition is not true, it assigns the other value. There is also an AND function, which returns true if all given conditions are met, and an OR function, which returns true if any of the given conditions are met.