1) They're the sounds a mechanical clock makes. Tick, tock, tick, tock as the pendulum swings back and forth.
2) The value of time tic command is the internal timer value at the moment the command is called. It's a big number because it's in small fractions of a second, but you shouldn't rely on the value of the number. It's only meant to be used as a relative input; relative to toc
3) Yes.
You can answer most of these questions by looking at the documentation by typing help tic or help toc
