- Digital Signal Processing (DSP) involves discrete operations on signals like shifting, flipping, and scaling. - Signals can be decomposed into even and odd parts using transformations. Periodic signals repeat after a certain interval. - Important signals include the delta function, unit step function, and their relationship. Signals can be represented in polar or Cartesian coordinates. - Real exponential and complex exponential signals are discussed. In discrete time, the lowest frequency is 1 and highest is the fastest possible digitization rate. - Ideal filters are aimed for but practical filters may differ. Periodicity of signals needs careful consideration in discrete time.