What is the main distinction between a half adder and a full adder?

The main distinction between a half adder and a full adder lies in the ability of the full adder to handle carry inputs from previous additions. A half adder is designed to perform the addition of two single binary digits (bits) and produces a sum and a carry output; however, it does not have the capability to accept an incoming carry bit from a previous addition operation.

On the other hand, a full adder is more advanced and is capable of adding three bits: the two significant bits and a carry bit from a previous addition. This feature allows a full adder to contribute to multi-bit binary addition, where carries from previous bits need to be included. Thus, when performing arithmetic operations involving multiple bits, full adders are essential for maintaining the accuracy of addition across all bits, especially in cascading configurations where the carry from one stage affects the next.