What is the definition of an infant in terms of age?

The definition of an infant typically refers to a young child in the early stages of life. Specifically, an infant is defined as a person from birth to the age of 2 years. This timeframe captures the critical developmental milestones that occur during this period, including significant physical, cognitive, and emotional growth.

While some sources may vary slightly in their definitions—with options centering on different age brackets—the most widely accepted definition encompasses the range from birth through the second birthday. This understanding is significant for medical, psychological, and developmental contexts, where recognizing the unique needs and characteristics of children in this age group is essential.

The other options suggest different age cutoffs that do not accurately represent the standard definition of an infant. For example, defining an infant as someone under the age of 1 or under the age of 3 fails to acknowledge the commonly accepted range of infancy that extends until the age of 2 years.