Fleshy stone fruit from plants in the Prunus genus
Cherries are fleshy stone fruits that grow on the plants of the genus Prunus.
"Cherry" can be used as a catch-all term that encompasses other fruits from genus Prunus where the fruits have other common names such as plums, peaches and apricots.
Cherry trees are smaller trees, grown for their fruit or flowers (blossom). Most "flowering cherries" produce no fruit or inedible fruit (e.g. large stone, little flesh).
The small red or black fruit (as seen in the below photo) is often known as a cherry blossom, cultivated from Prunus avium.
Photo: "cherries" by D H Wright.