Infanzia vs. fanciullezza
In Italian, both infanzia and fanciullezza translate to childhood, but they are not perfect synonyms. They refer to different, though sometimes overlapping, stages of a person's early life, with infanzia being the more general and common term.
Infanzia
A2This is the most common and broad term for childhood. It primarily refers to the earliest phase of life, from birth up to the age of 6 or 7. This period covers being an infant, a toddler, and a preschooler. By extension, infanzia can also be used more generally to refer to the entire time one is a child.
Ho trascorso la mia infanzia in un piccolo paese di campagna.
(I spent my childhood in a small country town.)
La scuola dell'infanzia in Italia è per i bambini dai tre ai sei anni.
(Preschool in Italy is for children from three to six years old.)
Molti ricordi della mia prima infanzia sono legati a mia nonna.
(Many memories of my early childhood are linked to my grandmother.)
Secondo lo psicologo, quel trauma risale alla sua infanzia.
(According to the psychologist, that trauma dates back to his childhood.)
Fanciullezza
B2This term describes a more specific stage of childhood that typically follows infanzia. It refers to the period from around age 6 or 7 up to the beginning of puberty (around 11-13). It is the age of a fanciullo or fanciulla (a school-age child), corresponding to the primary school years. This word often carries a slightly more literary, formal, or nostalgic tone than infanzia.
Durante la sua fanciullezza, amava passare i pomeriggi a leggere libri di avventura.
(During his childhood, he loved to spend afternoons reading adventure books.)
È un film che cattura perfettamente la spensieratezza della fanciullezza.
(It's a film that perfectly captures the lightheartedness of childhood.)
La fine della fanciullezza coincide con l'inizio dell'adolescenza.
(The end of childhood coincides with the beginning of adolescence.)
Le amicizie strette durante la fanciullezza sono spesso le più durature.
(Friendships made during the childhood years are often the most lasting.)
Summary
In summary, infanzia is the general term for childhood, but its core meaning is early childhood (approx. 0-6 years). Fanciullezza is more specific, describing the period of a school-age child before puberty (approx. 6-12 years). If you need to talk about childhood in general, infanzia is always a safe choice. Use fanciullezza when you want to specifically evoke the image of a primary school-aged child who is no longer a toddler but not yet a teenager.