The chord symbol iii could be followed by the letter a to indicate that it is F# minor chord in root position (ie not inverted) - D major scale chord iiia. Instead, iii could be followed by the letter b to indicate that it is F# minor chord in 1st inversion - D major scale chord iiib.
According to the Centers for Disease Control and Prevention, a baby is considered an infant until he reaches one year of age. During this stage, the infant reaches several developmental milestones.
A small child is commonly referred to as a baby irrespective of his age though there are developmental stages in the first few years of the life of a human offspring. The smallest of babies are the newborns in the first few days of their lives. Infant is a word that is reserved for a kid before the age of 1 year. So, if you have a baby boy or girl who is a few months old, the doctor would refer to him or her as an infant. However, there are many grandmothers and grandfather who would take exception of this definition and call their grandchildren babies even when they are much older because of their extreme love for their grandkids.