YouTube is a visual guide I believe. Because 4 months before I bought new 4G Android mobile. Many seatings were not known for me. And last month my mobile was showing notification as my trash is full and I should delete some files. I was searching in settings for trash. But I did not get it. Finally I searched YouTube video for relative topic and got answer. It is very simple to understand from YouTube videos whatever I want to understand. It has helped me by visual understanding which is apriciable. I have saved some important videos in offline in YouTube which helps me when I forget some important setting or topics.