Demo

noun

1. A demonstration or visual explanation.

   "The professor prepared a demo to help her class understand the topic."

2. A recording of a song meant to demonstrate its overall sound for the purpose of getting it published or recorded more fully.

   "After hearing the demo the record label approved funding to record the song with a full band."

3. An example of a product used for demonstration and then sold at a discount.
4. A march or gathering to make a political protest.
5. An edition of limited functionality to give the user an example of how the program works.

   "The game's developers released a demo version to the public 3 months before the full release."