Diff Two Arrays, method recommend is confused

Hi, I am a little confused by the method recommended .slice() because I can’t figure how to use in the challenge(Diff Two Arrays), I found the solution in the forum and for my surprise, the solution not have it, instead have the method .includes(), I guess shall changed in the list of recommend method, or I wish know if someone resolved it with the method .slice(). Thanks!!!

Thank for reply my post, of course, I continue trying, I mean that viewed the solution only searching for the method .splice(), because I found it interesting used the method for resolve the problem, and I understand that the suggestions are guides, thanks for the advise, only wished I know if the method was more interesting in this challenge.