can i use a picture that is in my device not on internet as a background-image?if yes,how?

Answer 1

https://stackoverflow.com/questions/851724/css-background-image-what-is-the-correct-usage

Answer 2

If you want to insert an image that is in your local storage you have to write the exact file path of that specific image. Such as...

background-image: url("file:///sdcard/Download/image.jpg")

Answer 3

...and unless everyone has the same file, linking using file:/// means only you will see them :)