According to Wikipedia:
A toddler is a young child who is of the age of learning to walk,  between infancy and childhood. Toddling usually begins between the ages of 12 and 18 months.  During the toddler stage, the child also learns a great deal about social roles, develops motor skills, and first starts to use language.
The term infant (baby) derives from the Latin word infans, meaning "unable to speak." It is typically applied to children between the ages of 1 month and 12 months. However, definitions vary between birth and 3 years of age.
Some people’s terms are overlapping
• The word baby means any child from birth to age 3.
• Toddlers are from one year to four years of age.
Some people have specific ages for each
• Infant is under a year.
• Toddler is between 1-3 years.
Some people’s terms are based on development
• A toddler knows how to walk.
• An infant is still learning.
Some people go by what clothes that the child is wearing
• Infant is baby to say about 2ish 3ish.
• Toddler age when their clothes sizes have a T at the end. Like 4T or 5T.
The Difference Between Toddlers and Babies (According to This Mom)
I’m inclined to go with the definition that states that a toddler knows how to walk and is starting to talk and a baby is still learning. In that respect, Sam would still be considered a baby.
That’s my story and I’m sticking to it.