In Exodus 39:42, "...the children of Israel did all the work," the word for work is Avodah. In Exodus 39:43, "And Moses saw all the work...", the word for work is M’lachah. What are the differences in these words, and why are they used here in this way, and in this order?

The Malbim explains that avoda is the more general work, as opposed to melacha which is the more refined artisan work, which is more visible to the naked eye, thus “Moshe saw (!) all the melacha”. See also 36, 2, where Betzalel, Ohaliav and the gifted artisans do “melacha”. Similarly the prohibition on Shabbat is called melacha (20, 10) which is particularly the 39 types of constructive creativity, yet doesn’t include crude labor such as lifting or pushing heavy objects (which is only a rabbinical commandment, not from the Torah).