please explain this insert statement...it works, but i have never seen it before

Dim Qry as String
Dim NumberOfRows As Integer=100 '----------> FOR 100 ROWS
Dim NumberOfColumns As Integer=8 '---------> FOR A through H Seats
Dim PlaneID as String="3434278231"
Dim SeatType as String

For i=1 to NumberOfRows
    For j=1 to NumberOfColumns
        If j=1 Or J=8 Then
            'Assuming A & H are Window Seats
            SeatType="Window"
        Else
           'More If Blocks might come here as per Seating arrangement
           SeatType="Aisle"
        End If
        Qry=String.Format("INSERT INTO TBL_SEAT (SEAT_NUM, SEAT_ROW, SEAT_TYPE, PLANE_ID) VALUES ('{0}', {1},'{2}', '{3}');",Chr(64+j),i,SeatType,PlaneID)

    Next j
Next i

what does this part do:
 ('{0}', {1},'{2}', '{3}');",Chr(64+j)