baby & infant 的分別

Baby - we are talking about newly born children, generally before they reach 2 years old we can call them baby.
Infant - it can refer to baby, while it can also refer to juveniles. Every country has its own definition about juveniles, but the general concept is that we call young people who has not become an adult to be a juvenile.
Examples :
1. Mary is busy taking care of her little baby so she has to wake up the whole night through. (You only have to take care of real little baby during the night.)
2. When we were infants we always thought that the world is wonderful. (A baby cannot have this kind of feeling. Only elder child or youngsters have such feeling.)

2008-10-16 03:07:47 補充：
Please see attached difinition for Cambridge Dictionary for your reference :

infant (SCHOOL)
related to or connected with the first stage of school in the UK, for children aged 4 to 7 years:
an infant teacher/class

2008-10-16 03:11:04 補充：
Here is the web site for Cambridge Dictionary regarding infant :

http://dictionary.cambridge.org/define.asp?key=40538&dict=CALD

Please note above is the defination of infant in UK. May be American uses it differently.

2008-10-16 03:11:24 補充：
Here is the web site for Cambridge Dictionary regarding infant :

http://dictionary.cambridge.org/define.asp?key=40538&dict=CALD

Please note above is the defination of infant in UK. May be American uses it differently, but I think we should stick to the UK definition when we are learning English.

baby = 嬰兒

infant = 幼兒

source : ttp://babyproducts.about.com/od/faqs/f/babyfaq.htm
Question: What's the Difference Between Baby, Newborn, Infant & Toddler?
Answer: On this site, the word baby means any child from birth to age 4. Newborn refers to babies under three months of age. Infants are babies from three months to one year old. Toddlers are babies from one year to four years of age.