Orthography is a noun that refers to the conventional spelling system of a language. 

The Greek word orthos (OR those) means ‘correct,’ while the suffix G-R-A-P-H-Y comes from the Greek word for ‘writing.’ So our word of the day may be used to refer to the way of spelling a word. Here’s an example:

My daughter is such a word nerd that when I asked her how cat was spelled, she gave me a ten-minute dissertation on the orthography of the word. I didn’t want to know why the word was spelled that way — just how it was spelled.