@ msbbarrat I agree with your viewpoint but i'd like to clarify a few points. analog circuits use a continuously variable signal where as digital circuits use an interrupted signal . both analog and digital circuits can be INTEGRATED Circuits or DISCREET Circuits . Both do the same job . Both use transistors capacitors etc . The difference ofcourse is as you stated in a discrete circuit you can swap out individual components like transistors or capacitors . In an IC Integrated circuit however the manufacturing process in microscopic and its all on one chip . so its physically impossible to figure out what transistor has blown , some will fail during the life of the circuit but there is an acceptable amount of multiplexing going on to keep things chugging along smoothly . Unless ofcourse some critical part fails in which case you have to replace the entire board / chip etc. IC offer much more redundancy , weight savings , efficient power use and ease of repair-ability when compared to discreet electronics. Now the switch to digital circuits took place because it is much more difficult to engineer analog circuits and analog signals are prone to interference/ noise , much more precise signal control is required .