Guys I need some helppo

What is reading with understanding ? Is it the same as unseen passage? I'm actually not comfused about this but what I'm actually wondering is I have refrence books not actual books. So this book has like 5 reading with understanding and they are almost like chapters to ab smjh nhi araha ki YHI reading with understanding same exams mai ayegi ya phir ye bas examples hai? Im in 12th btw