Password protecting files and folders

I know this question has been asked awhile back but its been years ago since Ive seen it answered. If it has been answered recently and I just missed it, Im sorry and I apologize. But, I was wondering if there was any way to put personal info such as tax returns, receipts, business documents and things of that nature in a file or folder that is password protected and cant be accessed if you dont know the password? You would think Apple would have a way of doing that but I havent found a way to yet. If anyone could tell me if this is possible and how do do it, it would be GREATLY appreciated. Thanks in advance.