Each product (AND) term is a Minterm. ANDed product of literals in which each variable appears exactly once, in true or complemented form (but not both). Each minterm has exactly one '1' in the truth table. When minterms are ORed together each minterm contributes a '1' to the final function. Note that all product terms are not minterms.
PRODUCT OF SUMS ( AND of OR terms)
The POS expression is the equation of the logic function as read off the truth table to specify the input combinations when the output is a logical 0. To illustrate, let us again consider Table 1-14. Observe that the output is low for the rows labeled 0, 1, 2, 4 and 7. The POS expression for this circuit is thus given by any of the following:
