low does the calculation method for the S&P $500$ differ om that of the Dow Jones Industrial Average $($DIIA$)?$

The S$8$P $500$ is a price$-$weighted index, whereas the DJA is a market$-$capitalization$-$weighted index.

The SBP $500$ is a market$-$capitaliration$-$weighted index, whereas the DMA is a price$-$weighted index.

Both the SSP $500$ and the DUA are calculated based on the share price of the included companies.