Demonstration (noun)

1. A public display or show to protest against something or to show support for a cause.
2. A display or exhibition of something, such as a product or idea, in order to explain or prove it.

Origin:

From the latin word 'demonstratio', meaning 'proof' or 'exhibition'.

Examples:

1. The demonstration was peaceful but loud, with protesters chanting and carrying signs.
2. The company's sales representative gave a demonstration of the new software at the trade show.
3. The cooking competition was won by the chef who gave the best demonstration of his skills.
4. The science fair was filled with demonstrations of innovative and creative projects.
5. The students organized a demonstration to protest the proposed cuts to education funding.