Definition of "Demonstration" :

noun: a show or display; the act of presenting something to sight or view

"He gave the customer a demonstration."

noun: a show of military force or preparedness

"He confused the enemy with feints and demonstrations."

noun: a public display of group feelings (usually of a political nature)

"There were violent demonstrations against the war."

noun: proof by a process of argument or a series of proposition proving an asserted conclusion

noun: a visual presentation showing how something works

"The lecture was accompanied by dramatic demonstrations."