[cartan]

I don’t know what Adobe Illustrator does there, but this is not a multi-layered PDF. In the ordinary Adobe Reader that everybody has installed, you can open a PDF, choose View > Navigation Panels > Layers, and you will see the multiple layers, if any. There are none in this PDF. Adobe Illustrator probably generates them, I guess.

[paulycy]

There are none in this PDF. Adobe Illustrator probably generates them, I guess.

It turns out that you can see the layers in other programs that work like adobe illustrator, like inkscape, which I've used to see the layers myself.

[D-fendr]

There are none in this PDF. Adobe Illustrator probably generates them, I guess.

I'm tempted to say "close enough" on this. But it's more complicated. PDF is Adobe owned and quite complex (it needs to be to work on all systems). Adobe licenses PDF in various ways. Apple, for example, buys the whole thing and, last I recall, Microsoft buys none. Various other vendors can license parts are all or build some kind of converter, etc.

Adobe Illustrator is unique in the PDF world. It is an Adobe product, it can use PDF as its native file format, it works with both vector and raster object and can convert and operate on both.

So, the questions of what Illustrator does or doesn't have to do to a PDF file versus others that license part or all of Adobe PDF is likely quite a ball of wax.