Maturation is the process of growing up and becoming fully developed — not the finished state, but the stretch of time during which the growing happens. It is a formal, technical word.

Maturation成熟 is是 the process of growing up and becoming fully developed長大、發育完全的過程 — not the finished state不是完成後的狀態, but而是 the stretch of time during which the growing happens成長發生的那段時間。It它 is是 a formal, technical word正式、專業的詞。

Where you would say in ordinary English 'children grow up at different speeds', a textbook says 'the rate of maturation varies'. That is the real difference between this word and 'growing up': the register, not the meaning.

in ordinary English你若用日常英文 you would say會說 'children grow up at different speeds'「孩子長大的速度不一樣」, a textbook教科書 says會說 'the rate of maturation varies'「成熟的速率因人而異」。That那 is是 the real difference真正的差別 between this word and 'growing up'在這個詞跟「growing up」之間: the register, not the meaning差別在語域（正式程度），不是意思。

You meet it mostly in three places. In biology and medicine: the maturation of cells, of the brain, of an insect. In psychology and education: emotional maturation, the maturation of language skills. And in food and drink, where it means the slow improvement that comes with time — the maturation of cheese, wine, or whisky in barrels.

You meet it mostly in three places你主要會在三個地方遇到它。In biology and medicine在生物和醫學裡: the maturation of cells細胞的成熟, of the brain腦的成熟, of an insect昆蟲的成熟。In psychology and education在心理學和教育裡: emotional maturation情緒的成熟, the maturation of language skills語言能力的成熟。And而 in food and drink在食物和飲料裡, where it means在這裡它指的是 the slow improvement that comes with time隨時間慢慢變好 — the maturation of cheese, wine, or whisky in barrels像起司、酒、威士忌在木桶裡的熟成。

Note it is normally uncountable ('a period of maturation'), and you talk about the maturation OF something.

it它 is normally uncountable通常是不可數名詞 ('a period of maturation'像「a period of maturation」), and而且 you talk about the maturation OF something要說「什麼的成熟」時用的介系詞是 of。

English also has a plainer noun, 'maturity', and students mix the two: maturity is the state you arrive at, maturation is the journey there. A twenty-year-old has reached maturity; the brain's maturation continues into the mid-twenties.

English英文 also有 a plainer noun另一個比較平實的名詞, 'maturity'「maturity」, and而 students mix the two學生常把兩個搞混: maturity「maturity」 is指的是 the state you arrive at你到達的那個狀態, maturation「maturation」 is指的是 the journey there到那裡的過程。A twenty-year-old一個二十歲的人 has reached maturity已經到達 maturity（成熟狀態）; the brain's maturation腦部的成熟（maturation） continues into the mid-twenties會持續到二十五歲左右。