how to get rid of the previous search result in vim

the_return_of_the_Ring

my book didn't tell me about this, so ask for help here.

u know, use "/" followed by the keyword can do the search in vim and the matched text will be highlighted in the text. the problem for me is, next time when i loaded in another file, the former keyword is highlighted in the new file, like I did the same search on the new file. How to get rid of it? i just want it to act like there's no search thingy happening before.