CSS Grid Layout implements the specification Box Alignment Level 3 which is the same standard flexbox uses for aligning items in its flex container. This specification details how alignment should work in all the different layout methods. Layout methods will conform to the specification where possible and implement individual behavior based on their differences (features and constraints). While the specification currently specifies alignment details for all layout methods, browsers have not fully implemented all of the specification; however, the CSS Grid Layout method has been widely adopted.
This guide presents demonstrations of how box alignment in grid layout works. You will see many similarities in how these properties and values work in flexbox. Due to grid being two-dimensional and flexbox one-dimensional there are some small differences that you should watch out for. So we will start by looking at the two axes that we deal with when aligning things in a grid.