The default value of the CSS declaration 'align-content' is 'normal'. However, there is another declaration: 'stretch', and I'm struggling to identify a single difference between the two of them. Are they identical (with perhaps one of them being obsolete)?
I played around with the Inspector tool on Chrome on a test website I created using HTML and CSS, and did the between those two values made zero difference in the appearance of the site.
These are the definitions on MDN:
align-content: normal: The items are packed in their default position as if no align-content value was set
align-content: stretch: If the combined size of the items along the cross axis is less than the size of the alignment container, any auto-sized items have their size increased equally (not proportionally), while still respecting the constraints imposed by max-height/max-width (or equivalent functionality), so that the combined size exactly fills the alignment container along the cross axis.
but i think in the browser the normal and stretch values pretty much work the same way for most cases. the different is that with stretch 'auto'-sized items to fi the container
There is also some good information here and here on CSS_Tricks
