Q.Distinguish between half adder and full adder.

A half adder adds two single bits and produces a sum and a carry, but has no input for a carry from a lower stage; a full adder adds three bits (the two operand bits plus a carry-in) and produces a sum and a carry-out. …

[!TLDR]

A half adder adds two bits (no carry-in); a full adder adds three bits including a carry-in, so full adders can be cascaded for multi-bit addition.

Both circuits perform binary addition, but they differ in how many bits they add.

Half adder: it adds two single-bit numbers A and B and generates two outputs — the SUM $(A \oplus B)$ and the CARRY $(AB)$. Because it has no third input for a carry coming from a lower-order stage, half adders cannot by themselves be chained to add multi-bit numbers. …