A few photos of my girls & now boys included!

[Lejays17]

In the States, that... string that you use for knitting... is usually called yarn. Is the term "wool" in Australia? Or is there a difference between yarn and wool? Or is it wool yarn, and is the example in this photo a cotton yarn that has been treated or manufactured to perform more like wool? (I apologize for my colossal ignorance when it comes to textiles)

Here any type of string you knit/crochet with is referred to as wool, especially with “older” people, regardless of what it’s made of.
It leads to funny conversations at my knitting groups.
“What wool are you knitting that thing with?”
“It’s a lovely silk/merino blend.” Or “it’s bamboo/linen/cotton” - the first does contain wool but the second doesn’t.

I try to remember that it’s referred to as yarn on the international knitting forum I belong to because I get tired of rude nit-pickers who tell me I’m wrong or ignorant for calling it wool.
(They then generally trip up by calling any fibre from an animal wool. This is incorrect, only fibre from sheep is wool, other animal fibres are called other things. They also take people to task for spelling things “wrong”, failing to realise it’s not just people from their part of America posting on the forum, and different parts of the world spell/refer to things differently)
You weren’t rude in asking a genuine question about it it’s just tripped my rant button.