The discussion clarifies the concept of real and imaginary parts of complex signals, represented as z = a + ib, where 'a' is the real part and 'ib' is the imaginary part. It explains that the imaginary part can be defined as Im(z) = b, a real number, and provides formulas to extract the real and imaginary components using the complex conjugate. The conversation highlights that complex numbers are often used in engineering to simplify mathematical problems, although all physically realizable signals are real. Additionally, it emphasizes the two-dimensional nature of complex numbers, with real and imaginary axes. Understanding these components is essential for grasping complex signal analysis.