About tools to simulate circuits. Specify the tool used.

Simulations use mathmatical models to predict the behaviour of a circuit. The Wikipedia article is a good starting point to learn more. This tag should be used for questions related to circuit simulation tools (software).

Questions specifically about the popular SPICE simulator, or one of its many descendant , should also be tagged .

Typically circuits are described to the simulator in either a text file (like a SPICE netlist) or as a graphical .