- A half adder adds two 1-bit binary numbers and produces a sum and carry output. It uses one XOR and one AND gate. The full adder adds three 1-bit binary numbers (two inputs and a carry input) and produces a sum and carry output. It is made up of two half adders joined by an OR gate.
- The key difference between a half adder and full adder is that a full adder has a third input for the carry input from the previous addition, while a half adder only has two inputs and is used as a basic building block for full adders. A full adder allows adding multi-bit binary numbers by chaining full adders together and