The idea
A spreadsheet is a street of houses
Columns have letters. Rows have numbers. Every box sits where one letter meets one number, and that pair is its address.
C5 means column C, row 5. Say the letter first, always.
A B C
4 Product Units Price
5 Croissant 120 60 <- C5 holds 60
CellOne box. It holds a number, some text, or a formula that works something out.
RangeA block of cells, written with a colon. B5:B10 is the six cells from B5 down to B10. A5:C10 is the rectangle three columns wide and six rows tall.