Final answer:
The algebraic expression (XY)' represents the NOR function in digital logic, while a buffer produces the transfer function by reproducing its input as output without changing its value.
Step-by-step explanation:
The algebraic expression (XY)' represents the NOR function. In digital logic, the NOR function is a combination of the OR function followed by a negation (NOT). If both inputs X and Y are false, the output of the NOR function is true. Otherwise, the output is false. This can be verified using a truth table where all combinations of X and Y are false except when both are false, yielding a true output for the NOR gate.
A buffer produces the transfer function. A buffer in digital circuits is designed to reproduce the input it receives as its output, effectively transferring the input signal to the output without changing its value. It can be thought of as a digital wire, ensuring that the signal is not weakened over distance or through connection to other circuit elements.