\v_c said:If I recall correctly, cascade would refer to a connection where the output of stage #1 would be the input of stage #2, output of stage #2 would be the input of stage #3, etc. If you think in the context of ABCD parameters for example, the total ABCD parameter of multiple systems in cascade is the matrix product of the individual ABCD matrices. Take a look at this for more information h**p://mysite.wanadoo-members.co.uk/phil_robinson/twoport.html
When you say two things are in series, to me what that means is that they have the same current going through them.
I hope that this gives you some ideas.