Part 1 - The Formula
Let's say you have the following two cells (B2 and B3, respecitvely):
INT() will round a number down to the nearest integer.
When you run
=INT(B2)=B2, it evaluates the first part,
INT(B2) which will return simply
3. Then it checks is
3=3? Yes it does, so it returns
TRUE for the whole formula.
When you run
=INT(B3)=B3, it evaluates
INT(4.3) which returns the next whole number when rounding down, in this case
Then it checks
4=4.3 which returns
FALSE for the overall formula.
Part 2 - The Referencing
When you have the formula applied to the range
A2:D60 (I'm assuming this is the "Applies To" range), you will be running the formula on ALL cells within that range.
If you removed the absolute references in the formula, the formula would evaluate on every cell in your range, regardless of column. in
C23 the formula would be
=INT(C23)=C23. See below - the formula actually being run in that cell is
6.5 is not an integer, it returns
FALSE and therefore no formatting is applied.
Since you want to check only column B for the integer, you need the absolute reference. That means on cell
C23, the formula being evaluated is
The "Applies To" range will then apply whatever formatting you have - so if
A23:D23 should have your formatting.