There are lots of apps available in the Play store to do this task, But Here in this tutorial i am gonna show you how to hide files in your Android device without installing any Third party application. The process is very simple and Easy to understand.
How to do:-
just follow below steps:-
1: Go to file manager like shown in the below pic.
2: Long press the file or folder which you want to hide. select options and click rename.
3: Add a dot(.) before name of file or folder as shown in below pic. it will be hidden.
To get file back just go to file manager and click options and click show hidden files and folders. and rename it back.