The acronym "CSE" stands for "Control + Shift + Enter". A CSE formula in Excel is an array formula that must be entered with control + shift + enter. When a formula is entered with CSE, Excel automatically wraps the formula in curly braces {}.

In the example shown, the formula in F5 is:

```
{=SUM(C5:C14*D5:D14)}
```

This array formula provides "total sales" in one cell, without a separate column and formula to multiply quantity times price. The curly braces are a clear indication that the formula was entered with CSE. If the same formula is entered *without* CSE, the result is incorrect.

### Not all array formulas require CSE

Not all array formulas need to be entered with CSE. Entering a formula with CSE explicitly disables a behavior in Excel called "implicit intersection", but some functions do this natively. For example, in the example shown, the SUMPRODUCT function can be be used instead of SUM without CSE:

```
=SUMPRODUCT(C5:C14*D5:D14)
```

The SUMPRODUCT formula returns the same result, but does not require CSE.