Palmar grasp

A grasp is an act of taking, holding or seizing firmly with (or as if with) the hand. An example of a grasp is the handshake, wherein two people grasp one of each other's like hands.

In zoology particularly, prehensility is the quality of an appendage or organ that has adapted for grasping or holding.

The development of grasping is an important component of child development stages, wherein the main types of grasps are:

The palmar grasp reflex (sometimes simply called grasp reflex) is among the primitive reflexes and appears at birth and persists until five or six months of age. When an object is placed in the infant's hand and strokes their palm, the fingers will close and they will grasp it. The grip is strong but unpredictable; though it may be able to support the child's weight, they may also release their grip suddenly and without warning. The reverse motion can be induced by stroking the back or side of the hand.

...
Wikipedia