An explanation of the Z transform part 1 by
David Dorran
https://www.youtube.com/watch?v=B4IyRw1zvvA&fbclid=IwAR33OAe98uxc9VEUWUm5E3vG1dJr1SkLcd4dz–KYbXOxr9zYH8aAtpVyjc