The correct way to insert specific words at the top of every page of a multi page essay is the third option - Type the words onto the first page after selecting the header region of the document by clicking the top edge of the page; it will automatically be repeated in all subsequent header regions of the document.
The steps in the third choice are correct for inserting a header. You should also keep in mind that you can also set the header so that it does not start until the second page, which may be appropriate for an essay.
Semantic search is simply search with meaning. It is designed to locate information based on the nature and meaning of Web content, not simple keyword matches (like in lexical searches)
