OS Details

Samsung Galaxy J7 Prime2 has been launched in March 2018.
Samsung Galaxy J7 Prime2 have Android 7.0 (Nougat), upgradable to Android 9.0 (Pie)

Screen Dimensions

Samsung Galaxy J7 Prime2 screen size is 5.5 inch with ~ 73.3% body ratio of actual device size. Physical dimensions for Samsung Galaxy J7 Prime2 device is 5.97 x 2.95 x 0.31 INCH or ( 151.7 x 75 x 8 MM).

Displaying of Units are in this order "Height x Width x Thickness"

Screen Pixel Density and CSS Pixel Ratio

"Pixel" is smallest unit/element of any display.

The total number of pixels that fit into an inch is referred to as "Screen Density" or "Pixel Density" and it measured as "Pixels Per Inch".
Pixel Desnsity have limits to display Pixels Per Inch depends on different screen sizes. When number of pixels per inch increases than it's screen-size limit, the Display resolution will increase but actual device width/height in pixels remain same. Actual device pixels are known as Device Independent Pixels or CSS Pixel Ratio.

Samsung Galaxy J7 Prime2 resolution is 1080 x 1920 ^PX with ~ 401 pixel desnsity.
Samsung Galaxy J7 Prime2 viewport size is 412 x 732 ^PX with ~ 153 actual pixel density, which means it have 2.625 xxhdpi display pixel density.

Screen Resolution and Viewport

The sum of pixels which are displaying on a device is called as "Screen Resolution". and sum of actual pixels of any device is reffered to as "Viewport".

Samsung Galaxy J7 Prime2 have 5.5" physical screen size and its resolution is about 1080 x 1920 Pixels with approximately 401 PPI pixel density. Samsung Galaxy J7 Prime2 has viewport size 412 x 732 Pixels and its pixel ratio is about 2.625.

For better understanding screen actual sizes, viewport sizes, display resolution and about their density click here.

CSS Media Queries

Samsung Galaxy J7 Prime2 Media Queries (In terms of Mobile only)

@media only screen and (min-width: 412px) and (max-width: 767px) { /* Your Styles... */ }

Samsung Galaxy J7 Prime2 Min-Width Media Queries

@media only screen and (min-width: 412px) { /* Your Styles... */ }

Samsung Galaxy J7 Prime2 Min-Height Media Queries

@media only screen and (min-height: 732px) { /* Your Styles... */ }

Samsung Galaxy J7 Prime2 Landscape Media Queries

@media only screen and (min-width: 732px) and (orientation: landscape) { /* Your Styles... */ }

Samsung Galaxy J7 Prime2 Portrait Media Queries

@media only screen and (min-width: 412px) and (orientation: portrait) { /* Your Styles... */ }

Samsung Galaxy J7 Prime2 Retina Media Queries

@media
  only screen and (-webkit-min-device-pixel-ratio: 2.625),
  only screen and (   min--moz-device-pixel-ratio: 2.625),
  only screen and (     -o-min-device-pixel-ratio: 2.625/1),
  only screen and (        min-device-pixel-ratio: 2.625),
  only screen and (                min-resolution: 401dpi),
  only screen and (                min-resolution: 2.625dppx) { 
    /* Retina styles here */
}
                                

Retina is actually based upon device pixel ratio. Devices mostly have 2x or 3x display so you can use general retina media queries to display high resolution content on all kind of devices. Retina 2x and Retina 3x media queries given below:

Retina 2x Media Query

@media
  only screen and (-webkit-min-device-pixel-ratio: 2),
  only screen and (   min--moz-device-pixel-ratio: 2),
  only screen and (     -o-min-device-pixel-ratio: 2/1),
  only screen and (        min-device-pixel-ratio: 2),
  only screen and (                min-resolution: 192dpi),
  only screen and (                min-resolution: 2dppx) { 
    /* Retina styles here */
}
                                

Retina 3x Media Query

@media
  only screen and (-webkit-min-device-pixel-ratio: 3),
  only screen and (   min--moz-device-pixel-ratio: 3),
  only screen and (     -o-min-device-pixel-ratio: 3/1),
  only screen and (        min-device-pixel-ratio: 3),
  only screen and (                min-resolution: 384dpi),
  only screen and (                min-resolution: 3dppx) { 
    /* Retina styles here */
}
                                

Samsung Galaxy J7 Prime2 Specifications

• Launch Date March 2018
• Android 7.0 (Nougat)
• Physical Screen Size 5.5 INCH
• Resolution 1080 x 1920 PX
• Viewport Size 412 x 732 PX
• Pixel Density 401 PPI
• Device-Independent Pixels 153 PPI
• Pixel Ratio 2.625 xxhdpi
• Width 1080 PX
• Height 1920 PX
• Device Width 412 PX
• Device Height 732 PX
• Dimensions 151.7 x 75 x 8 mm (5.97 x 2.95 x 0.31 in)
• Weight 170 g - 6.0 oz