Solved: Explain Code Please

[jhg1226]

The sub pasted below works just fine, but I do not understand why. Can anyone explain to me what the line of code highlighted in blue is doing?

Sub QuarterSales()

Dim RowCount As Integer
Dim QtrCount As Integer
Dim QtrSales(0 To 3) As Long

'Loop for every row (Region)
For RowCount = 2 To 41
'Loop to Calculate Totals for all quarters
For QtrCount = 0 To 3
QtrSales(QtrCount) = Cells(RowCount, (2 + (QtrCount * 3))).Value + Cells(RowCount, (3 + (QtrCount * 3))).Value + Cells(RowCount, (4 + (QtrCount * 3))).Value
Next QtrCount

'Checking condition Q1 > Q2 > Q3 > Q4
If QtrSales(0) > QtrSales(1) Then
If QtrSales(1) > QtrSales(2) Then
If QtrSales(2) > QtrSales(3) Then
'Applying RED color
Cells(RowCount, 1).Interior.ColorIndex = 3
End If
End If
'Checking condition Q1 < Q2 < Q3 < Q4
ElseIf QtrSales(0) < QtrSales(1) Then
If QtrSales(1) < QtrSales(2) Then
If QtrSales(2) < QtrSales(3) Then

'Applying BLUE color
Cells(RowCount, 1).Interior.ColorIndex = 5
End If
End If
End If
Next RowCount
End Sub

[jhg1226]

The code calculates quarterly values by multipling the vale to obtain the column in which the months fall. Jan is in column B, Feb in C and March in D.