My tablet offers a 1920x1200 resolution.
I noticed anything over 960px wide does not fit well on my Webpage.
Why on a 1920 wide tablet do I have to keep my images 960px wide or less?
My tablet offers a 1920x1200 resolution.
I noticed anything over 960px wide does not fit well on my Webpage.
Why on a 1920 wide tablet do I have to keep my images 960px wide or less?
As Andrew mentions, it's because the device is using virtual pixels rather than actual pixels. If it were to use actual pixels, your web pages would be stretched ridiculously wide and the type likely rendered at a size that would be difficult to read. You'd then resort to zooming and panning and now that the page is so wide, that would be a burden as well.
FYI, you can set the virtual width of your web page for devices using the viewport meta tag:
<meta name="viewport" content="width=800, initial-scale=1">
In the above example, the page is telling the device "render this page 800 virtual pixels wide, then zoom it all in to fit however many real pixels your device has.