The maximal resolution my graphics cards supports is 2560x1600, however there are no monitors on the market with this resolution, the closest one is 2560x1440.
What will happen if I connect such a monitor to my PC? Is everything going to look normal?
2560x1600 is a 16:10 aspect ratio (width:height). 16:10 used to be fairly popular for monitors before higher resolutions became more common. In the early 2000's up to about 2008, 16:10 was the way to go. Since then, not so much, except for laptop internal screens. 1920x1200 was a very popular laptop screen resolution, & indeed some laptops still come with 16:10 screens in higher resolutions.
In the meantime, everybody got "HD" TVs & monitors 1920x1080 - television broadcasts are in this resolution & aspect ratio… 16:9
Everyone else wanted to do the same thing, 16:9 became far more popular for all things screen-related.
Then came higher resolution external monitors to the mainstream… they're all 16:9. the older 16:10 ratio just wasn't popular any more.
So, no-one ever made a modern higher resolution 16:10 monitor.
Well, there might be some, somewhere, but they're certainly not common
It's fairly easy to specify 2560x1600 as a maximum resolution for a graphics card, as "maximum" also includes smaller.
2560x1440 is… wait for it… 16:9.
Everything that supports 2560x1600 also supports 2560x1440
