Since the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders(DSM-V) being autistic has become harder than before, especially if you’re truly in the category of being autistic, instead of being the so-called “Aspie”, which refers to those with Asperger’s syndrome.

It may seem easy, whether you have the Autism (disorder), Asperger’s syndrome, PDD-NOS, or Heller’s syndrome(CDD), you are autistic, that is at least if you refer to the autism spectrum disorders(ASD), which as of DSM-V has replaced the previous pervasive developmental disorders(PDD), which also included Rett syndrome.
The reality is different, as the previous dividing by those terms was actually quite important to do, even though it did cause stigma surrounding the first term, the autism disorder.
Not surprisingly actually, as a lot of people don’t understand that someone with Autism technically would have the Autism disorder and not any of the other named forms of PDD, a reality that has even become less notable with the introduction of the ASD category.

You may ask, what were the differences between those forms of PDD, or nowadays ASD, to begin with.
Well, the answer is why there is so much stigma and the move was made in DSM-V.
Between the Autism disorder and Asperger’s syndrome the difference are the specific complications experienced.
While PDD-NOS differentiated by a lack of clarity, it was a diagnosis for those who had quite a lot of symptoms of either the Autism disorder or Asperger’s syndrome, but didn’t fit in either one of those classifications.
As for Heller’s syndrome, that’s a whole different discussion in it’s own.
Nowadays Heller’s syndrome has actually become “regressive autism”, a sub-classification of autism, and is intended for those with an ASD which is said to develop at a later age (The same as CDD is about!).
It’s where the discredited claims of vaccines being responsible for an ASD probably come from, even though the reality of regressive autism actually existing being still an ongoing discussion.
So, in short, the differences are the complications, clarity, and regressivity, all of them depending on the type of ASD we are talking about.
This should also make clear why in most autism-related discussions you would only see the autism disorder and Asperger’s syndrome being used, as those are the 2 clear diagnoses of ASD.

Now, you may ask why it is so important for the difference between the autism disorder and Asperger’s disorder being clear to everyone.
Although the answer to that should already be clear by me stating that the difference is at the complications experienced, but let me be more specific than just that.

I am one of the people who is diagnosed with the Autism disorder and would fall into the category of high-functioning autism(HFA), a term I haven’t previously used as it’s not a recognized form of ASD.
HFA is a term that applies specifically to those with Autism disorder who have an IQ of 70 or greater, which obviously has never become a valid diagnosis because of the clear discrimination applied by using it.
Anyhow, being someone diagnosed with Autism disorder, I am clearly not someone with Asperger’s syndrome, and there is a clear way to state why.
Those with the Autism disorder generally have lower verbal reasoning skills, have a more open-minded way of interests and curiosities, are better at visual thinking (PIQ), are less clumsy in movement, and have more problems functioning independently than most people who have been diagnosed with Asperger’s syndrome.
Or in a more practical way of explaining, someone like me, diagnosed with Autism disorder, has more problems interacting with others and doing thing on his(/her) own, while being more open-minded than someone who has been diagnosed with Asperger’s syndrome.

And yes, those differences can be clear, very clear even.
Especially when you would compare the online activity of those with the Autism disorder (without an intellectual disability) to those with Asperger’s syndrome (without an intellectual disability).
In simplicity, most with Asperger’s syndrome are very outgoing and will have masses of (online) friends, while someone with the autism disorder have a small group of friends who he/she holds dear and close.
While at the same time, someone with autism disorder will generally more outreach and flexibility in conversation by being more open-minded in their interests and curiosities, while someone with Asperger’s syndrome generally is very focused on 1 specific subject.
Which both are advantageous in their own ways, while also being disadvantageous in their own ways.

Stating the difference is important as an aspie[someone with Asperger’s syndrome] is not someone who is autistic[someone with Autism disorder].
Apart of both forms of the disorders are recognized as an ASD, they are not actually truly similar.
Actually, someone who is an aspie is at a lot of social skills pretty much the opposite of someone who is autistic…