What is grid flow?
The grid-auto-flow CSS property controls how the auto-placement algorithm works, specifying exactly how auto-placed items get flowed into the grid.
What does 1 fr mean?
What's a fraction (1FR)? A fraction or 1FR is one part of the whole. 1 fraction is 100% of the available space. 2 fractions are 50% each. So, 1FR is 1/2 of the available space.
What is FR in CSS?
Thankfully, CSS Grid Layout introduces a new unit of length called fr, which is short for “fraction”. MDN defines the fr unit as a unit which represents a fraction of the available space in the grid container.