A question about a English grammar term?

Question

I used to read some English grammar books and learned the grammar term of the independent structure. For example, in the sentence
The iron content of tomato sauce cooked in an iron pot for 3 hours showed a striking increase, the level going up nearly 30 times.
the part of "the level going up nearly 30 times" is an independent structure.
but lately I read a new grammar book and found they use "the absolute structure" not "the independent structure" any more. I wonder whether this change is necessary and what's the difference.

Answer 1

In determining whether or not it is an independent structure or not, just ask yourself if the sentence would make sense when you take out a certain part. That part that could stand alone without the other is the independent structure.

There should be not be any difference from what they call it before and now. Both terms could co-exist. An independent structure ia an absolute one as it could stand by itself.

Answer 2

I learned english reading comics and listening in to shorwave broadcast back in the '80s.
I didn't "learn" english grammar, I internalized it, if you know what I mean.

Answer 3

Fashions change, even in grammar.

The terms are equivalent.

It's 'an English' btw.