This is the 23rd most frequent Urdu word.
جو
The Urdu word "جو" means "that" or "which" in English.
In this context, 'جو' introduces a relative clause, linking the sentence's subject 'the book' with the action 'I bought'.
جو کتاب میں نے خریدی وہ بہت خوبصورت ہے۔
The book that I bought is very beautiful.
Here, 'جو بھی' conveys an unspecified or indefinite condition, implying 'no matter what/which'.
جو بھی وقت لگے، ہم اپنی منزل پر پہنچیں گے۔
No matter how long it takes, we will reach our destination.
In this case, 'جو' is used to introduce a clause describing the subject, as in 'what happened'.