Now I know why zoom feature is available in operating system for.

I use to think why would an O/S feature is created as it sudden zoom ridiculous 10-100x of the current resolution. 

But as one age, it FINALLY make sense, all comes around! Let's give an example. Given the current view at current resolution of the following picture

Given the following webshot, what's the difference can you identify?

Sure, some with very good eye can spot but it would also take sometime to identify. But if you can zoom in, wouldn't that be nice?! In linux , try super + alt + 8, yes the 8 is not on the numpad. Now it should be clearly shown what is the difference.

The display might be too small, try open the image in a new window tab. It should be clearly seen that the vertical line is dashed whilst the horizontal line is dotted. Well that's the difference!

It is like the zoom feature allow one to inspect the DNA.. well, computer DNA.. :)