It is convenient to have access to a virtual simulator. Most professional ones use the solution engine SPICE under license of the University of California at Berkeley, to do the actual simulation. The package merely provides a nice graphical interface with SPICE. CircuitMaker is one of the friendlier interfaces that I have seen, and its student version is freely available. That is the reason for this brief video. If you are in my class, in your labs you’ll have access to the full version of MultiSim, from National Instruments, that is another graphical interface to SPICE. Each package, apart from the nice graphical interface, provides a library of components, that is models of actual diodes, transistors, etc., to include in the experiments. Libraries vary from one vendor to the next. CircuitMaker for students, is very powerful and its library is sufficiently large to serve our needs in this second year of your program. A colleague from UC linked the full zip file for CM at http://my.ece.ucsb.edu/York/Bobsclass/2C/Simulation/circuit_maker.htm.
That is very kind of him.