Q.Distinguish between AND – OR logic and OR – AND logic,

AND-OR logic is a two-level structure that implements a sum-of-products expression, while OR-AND logic is a two-level structure that implements a product-of-sums expression. …

[!TLDR]

AND-OR logic realises an SOP (AND gates then an OR gate); OR-AND logic realises a POS (OR gates then an AND gate).

Both are standard two-level gate arrangements, differing in which gate is at each level and hence in the standard form they implement.

AND-OR logic: the first (input) level consists of AND gates that produce the required product terms; their outputs feed a single OR gate at the second level that sums these terms. The overall output is therefore a sum of products (SOP). Example: $Y = AB + \overline{A}C$.

OR-AND logic: the first level consists of OR gates that produce the required sum terms; their outputs feed a single AND gate at the second level. The overall output is a product of sums (POS). Example: $Y = (A + B)(\overline{A} + C)$. …