Cell padding is used for formatting purpose which is used to specify the space needed between the edges of the cells and also in the cell contents.
Cell spacing is one also used f formatting but there is a major difference between cell padding and cell spacing. It is as follows: Cell padding is used to set extra space which is used to separate cell walls from their contents. But in contrast cell spacing is used to set space between cells.
Cell spacing and cell padding both are used for formatting purposes. The difference is, cell padding is used to specify the space needed between the edges of the cells, but cell spacing is used to set the extra space between the cell walls and their contents.