Keyboard Increment value Option
This setting already comes set to 1 px, but in case you have a different value, make sure to change it accordingly. Each time you are moving your shapes around using the arrow keys, this setting will help you a lot, since you’ll now be able to make super precise movements in those situations when using a mouse is painfully slower.
Quick tip: if your increments must be different, don’t worry since you can change it.
General Units Option
For each option, you can select from six different measurement units (points, picas, inches, millimeters, centimeters, and pixels). By default Illustrator sets it to Points but we will only use Pixels.
Stroke Units Option
We will set the Stroke to Pixels, since our General and Stroke settings have to match.
Guides & Grid
Gridline Every Option
A Gridline is a line (be it vertical or horizontal), that Illustrator draws in order to create the Grid. By default, the template is set to Gridline every 16 px, which means that at each 16 px it draws a vertical and horizontal line.
Tthe Subdivisions controls the number of sections that fall in-between those lines. Since we’re aiming for absolute precision, the template is set to 16. That give us a distance between lines of 1px.