What is the difference between max-device-width and max-width for mobile web?

max-width refers to the width of the viewport and can be used to target specific sizes or orientations in conjunction with max-height. Using multiple max-width (or min-width) conditions you could change the page styling as the browser is resized or the orientation changes on a device like an iPhone.

max-device-width refers to the viewport size of the device regardless of orientation, current scale or resizing. This will not change on a device so cannot be used to switch style sheets or CSS directives as the screen is rotated or resized.

max-width is the width of the target display area, e.g. the browser

max-device-width is the width of the device's entire rendering area, i.e. the actual device screen

Same goes for max-height and max-device-height naturally.

What do you think about using this style?

For all breakpoints which are mostly for "mobile device" I use min(max)-device-width and for breakpoints which are mostly for "desktop" use min(max)-width.

There are a lot of "mobile devices" that badly calculate width.

Look at http://www.javascriptkit.com/dhtmltutors/cssmediaqueries2.shtml:

/* #### Mobile Phones Portrait #### */
@media screen and (max-device-width: 480px) and (orientation: portrait){
  /* some CSS here */
}

/* #### Mobile Phones Landscape #### */
@media screen and (max-device-width: 640px) and (orientation: landscape){
  /* some CSS here */
}

/* #### Mobile Phones Portrait or Landscape #### */
@media screen and (max-device-width: 640px){
  /* some CSS here */
}

/* #### iPhone 4+ Portrait or Landscape #### */
@media screen and (max-device-width: 480px) and (-webkit-min-device-pixel-ratio: 2){
  /* some CSS here */
}

/* #### Tablets Portrait or Landscape #### */
@media screen and (min-device-width: 768px) and (max-device-width: 1024px){
  /* some CSS here */
}

/* #### Desktops #### */
@media screen and (min-width: 1024px){
  /* some CSS here */
}