Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

an electronic book (also called an e-book, ebook or digital book) is a book in digital form.
e-book

salhad is one of the 51 union councils (sub-divisions) of abbottabad district in the khyber pakhtunkhwa province of pakistan.
salhad

hip hope is a type of culture/art style that started in the 1970s.

hip hop