OS Details

Apple iPad Air (2020) has been launched in October 2020.
Apple iPad Air (2020) have iPadOS 14

Screen Dimensions

Apple iPad Air (2020) screen size is 10.9 inch. Physical dimensions for Apple iPad Air (2020) device is 9.75 x 7.03 x 0.24 INCH or ( 247.6 x 178.5 x 6.1 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.

Apple iPad Air (2020) resolution is 1640 x 2360 ^PX with ~ 264 pixel desnsity.
Apple iPad Air (2020) viewport size is 820 x 1180 ^PX with ~ 132 actual pixel density, which means it have 2.0 xhdpi 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".

Apple iPad Air (2020) have 10.9" physical screen size and its resolution is about 1640 x 2360 Pixels with approximately 264 PPI pixel density. Apple iPad Air (2020) has viewport size 820 x 1180 Pixels and its pixel ratio is about 2.0.

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

CSS Media Queries

Apple iPad Air (2020) Only Media Query which covers portrait to landscape width.

@media only screen and (min-width: 820px) and (max-width: 1180px)  { /* Your Styles... */ }

Apple iPad Air (2020) Media Queries (In terms of Tablets only)

@media only screen and (min-width: 768px) and (max-width: 1024px)  { /* Your Styles... */ }

Apple iPad Air (2020) Min-Width Media Queries

@media only screen and (min-width: 820px) { /* Your Styles... */ }

Apple iPad Air (2020) Min-Height Media Queries

@media only screen and (min-height: 1180px) { /* Your Styles... */ }

Apple iPad Air (2020) Landscape Media Queries

@media only screen and (min-width: 1180px) and (orientation: landscape) { /* Your Styles... */ }

Apple iPad Air (2020) Portrait Media Queries

@media only screen and (min-width: 820px) and (orientation: portrait) { /* Your Styles... */ }

Apple iPad Air (2020) Retina Media Queries

@media
  only screen and (-webkit-min-device-pixel-ratio: 2.0),
  only screen and (   min--moz-device-pixel-ratio: 2.0),
  only screen and (     -o-min-device-pixel-ratio: 2.0/1),
  only screen and (        min-device-pixel-ratio: 2.0),
  only screen and (                min-resolution: 264dpi),
  only screen and (                min-resolution: 2.0dppx) { 
    /* 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 */
}
                                

Apple iPad Air (2020) Specifications

• Launch Date October 2020
• iPadOS 14
• Physical Screen Size 10.9 INCH
• Resolution 1640 x 2360 PX
• Viewport Size 820 x 1180 PX
• Pixel Density 264 PPI
• Device-Independent Pixels 132 PPI
• Pixel Ratio 2.0 xhdpi
• Width 1640 PX
• Height 2360 PX
• Device Width 820 PX
• Device Height 1180 PX
• Dimensions 247.6 x 178.5 x 6.1 mm (9.75 x 7.03 x 0.24 in)
• Weight 460 g - 1.01 oz