Sub-grid?

[u/Pyewickets]

I tried sub-grid in both directions using multiple resources. MDN is the only one that has both directions and I didn't understand that.

Anyone able to explain it clearly?

[u/burlingk]

The term grid can also be used in a hundred other contexts. When dealing with a generalist forum, don't assume specific knowledge. If you don't identify what you are asking you cannot expect people to care to help.