This is the 526th most frequent Urdu word.
اچھی
The Urdu word "اچھی" means "good" in English.
Here, "اچھی" is used as an adjective describing the noun "کتاب" (book), denoting quality.
یہ ایک اچھی کتاب ہے۔
This is a good book.
"اچھی" in this sentence qualifies the noun "طالب علم" (student) and agrees in gender and number.
وہ ایک اچھی طالب علم ہے۔
She is a good student.
In this usage, "اچھی" modifies "زندگی" (life), indicating a desirable or positive quality of life.