Shades of grey on a scale.

Yes, hence the word Spectrum.  However, shades of grey blend together, whereas a spectrum is broken up in bands.

For example, a stripper can't just put on High Fasion clothes, and walk the runway that way, any more than a Glammour model knows how to work the pole.  (Unless she used to dance to get through college.)

Or in other words, IndustrieS.  Plural, not the same fucking thing.

The image you have in your head is Black and White.  Not colour, nor color.  No hue, tone, saturation, nor brightness to it, just approximately 50 shades of it.  Now, you're telling 2 people who work in/with those industries it's basically all the same.

It isn't.  There is a difference.  Several, in fact.

[Badman]

You are right I am wrong. Not all models are whores and not all whores are models.

Actual sex work is varied too, but there you have your greyscale.  With the exception of Specialties (Like BDSM) there isn't a whole lot of training, nor prerequisites to having sex for money.  Can you have sex?  Do you want to make some money?  That's about it.

So there the difference (Often translates to Price) is a matter of Setting.  Your street hooker is not going to charge as much as the luxury hotel on-call-girl.  However an irony in the industry is that a girl's prices can actually go down as she gets older, more experienced, but less attractive.  (Not always, nor even usually the case, but I have seen it happen.)

Please don't verbally abuse our members, by passive aggressively calling them whores.  It's rude.

[Badman]

You are right I am wrong. Not all models are whores and not all whores are models.

I assume 'whore' is offensive whereas sex workers/prostitutes/hooker/street hooker/on-call-girls is not?

You are right, I am rude. I will rephrase... 

Not all cartoons characters are animals and not animals are cartoon characters.

Is that different to;

Some cartoon characters are animals and some animals are cartoon characters

Is it true or is it false?

I assume 'whore' is offensive whereas sex workers/prostitutes/hooker/street hooker/on-call-girls is not?

It depends on the sex worker.  Here's where we get into more detail on what exactly the differences are:

"Sex work" is the whole shebang.  Pornography, hooking, stripping, dominatrix, and tea-room Huslting.  Sex+Work=Sex Work.  That's the Spectrum across the entire industry.

Prostitution is sex for money.  Specifically a consensual exchange of goods for services rendered, whether it's a hand job, or contract rap fantasy reinactiment in your personal dungeon.  Let's call that one end of the spectrum.

"Hooking" originally referred to turnpike prostitution.  "You need a ride?"    It also includes the Street walker, though can be a catch-all term for hit it and quit it 1 time deals.  She looks nice, "How much" entry level prostitution.

"Strawberry" is one you didn't specifically mention, but is an addict offering sex for drugs.  "Suck yo dick fo a rock!"

Call Girl is getting nebulous, but generally means "We deliver."  Originally, yes.  If you discretely asked the manager at a nice enough hotel, he probably had some numbers, but that was back in the days of Ma Bell.  Nowadays, they tend to use Craigslist, but at this level of the profession (Hookers are considered Amateurs) you can expect such things as TGFE, Fantasy, and a regular appointment.  "Same time next week, John?"  

Of course a Pimp/Madam is a Management position.

Technically a Whore works in a Whorehouse, however it's been used as an insult as well.  Pretty much since the term replaced Harlot in the lexicon.  The subdle difference is a Call Girl is order yout, while a Whore House is more like a Restraunt.  There you can also get TGFE, and they often have Fantasy rooms if you have something specific in mind.

However, it's always an insult when you equate stripping, porn stars, and modeling to Whoring.  It's not even the same industry.  Modeling isn't even sex work, though some models may also do sex work (Like pornography) on the side.  Much like a mechanic can fix your porch if he needs the money.