What is the basic difference between MUL and IMUL instruction in 8086 microprocessor?

mul is used for unsigned multiplication whereas imul is used for signed multiplication. Algorithm for both are same, which is as follows:

when operand is a byte:

AX = AL * operand.when operand is a Word:

(DX AX) = AX * operand.

But, the difference is that mul instruction multiplies only unsigned numbers whereas imul instruction does the same for signed numbers.