This is the 88th most frequent Japanese word.
自分
"Self" or "oneself."
Here, 自分 refers to oneself, in this case meaning 'your own'.
自分の名前をちゃんと書いてください。
Please write your name properly.
In this sentence, 自分 is used to emphasize possession, indicating 'one's own' ideas.
彼は自分の考えをしっかりと持っています。
He has firm beliefs of his own.
Here, 自分 refers directly to the speaker, equivalent to 'I' or 'myself' in English.