In criminal law, kidnapping is the unlawful abduction and confinement of a person against their will. Kidnapping is typically but not necessarily accomplished by use of force or fear; i.e., it also usually involves menace/assault or/and battery; but it is still kidnapping without those additional elements, or if a person is enticed to enter the vehicle or dwelling willingly.
K. J. Ståhlberg (in the center-right), the first President of the Republic of Finland, and his wife at the Helsinki Central Station after their kidnapping. In the middle of picture their daughter Elli Ståhlberg stands behind them.
The abduction of Dinah, (watercolor, c. 1896–1902 by James Tissot)
Arrested kidnappers in Rio de Janeiro, Brazil lying on the ground
Ransom is the practice of holding a prisoner or item to extort money or property to secure their release, or the sum of money involved in such a practice.
"The Ransom", John Everett Millais, c. 1860
Ransom note delivered to the family of Adolph Coors III in 1960