How to find a text and replace it with another text in the Microsoft word and what is the purpose?

It is a very easy thing to do, but mostly people don’t use this facility of word. It saves lot of time of a user. If there is one word that is used mostly in your whole document or in a paragraph and you want to replace that word with the other new word or there is some spelling mistake in the current word you used. For example you have used the word “spelling”, which is grammatically wrong. So you can replace it from your whole document easily without going the need of changing each and every word manually. You can use the find and replace option for it.