In spreadsheets you often repeat the same formula many times. In a programming language you would not write

C2 = B2/B1 - 1

C3 = B3/B2 - 1

C4 = B4/B3 - 1

ad infinitum. You would store the B's and C's in arrays and write a loop, or use array operations in languages that supported them.

In Excel, if you have stock prices in column B, you compute stock returns in column C by entering "=B2/B1 - 1" in cell C2 and copying the formula for the whole column. But nothing stops you from inadvertently changing the formula in cell C100.