Idon'tknow:
No need at all to worry that you might offend someone, or that anyone might think you stupid
I suppose 'Special needs' means children who need extra special help for conditions which mean they can't function in mainstream education or out on their own in the big bad world, for instance, or have physical or sensory impairments which can't be rectified by simple means like a pair of galsses.
Special Needs (SN) tends to include 'disability', which can be physical, sensory (e.g visual or hearing impairment), or 'cognitive' - also called learning difficulties, or learning disability.
Some SN arise from neurological problems, such as autism
NT: Neurologically Typical
DS: Down's Syndrome
AS: Aspergers Syndrome (an autistic spectrum disorder)
ADHD: Attention deficit and hyperactivity disorder
SALT: Speech and Language Therapist
AFO: Ankle/Foot Orthotic
(beginning to see why no-one would think anyone was stupid for not knowing what it all is? )
For me, SN does not include the little idiosyncracies or differences in ability which are at either end of 'average'. It is as a result of a particular condition. I do often use the word 'difference' because at the moment, i'm not sure whether my DS's lack of a fibula etc really is going to mean that he is 'disabled' - or simply a bit of a one-off model!
Hope this helps. Others may have a clearer - or different explanation than me - but whenever you are interested and are not sure what someone means, it will never cause upset or offence to ask. Honest!