This Latin word (imitatio) means imitation. To simulate means to imitate.
In art and in life, imitation occurs very frequently. Almost every person is able to mimic the style of talking, gestures and facial expressions of other people, the singing of birds, the voices of the animals. Some art forms - theatre, cinema, radio and television performances often have to simulate to simulate the sound of rain, the whistling wind, the thunder, the roar of the surf and other sounds.
In music the term "imitation" means a special welcome development. They called the repetition of a melody that sounded another voice or another instrument. Often imitation occurs in polyphonic works warehouse (the term "polyphony" and "homophony" are explained in the story about the polyphony).
If you had to listen to a Fugue by Bach or Shostakovich, then you probably noticed that begins Fugue monophonic. Then the melody, performed the first voice repeats the second is from another sound. Next, with the same melody enters the third and then the fourth voice.
Imitation occurs in homophonic music, but if it is a core polyphonic and absolutely indispensable receiving combinations of voices, the music is homophonic-harmonic stock, it is used only occasionally.