Is autism a disability?

My council had autism on the application form and didn't specify it had to be a certain level in order to be registered disabled with them.

This site refers to autism as a developmental disability:

www.autism.org.uk/.../what-is-autism

This link regarding discrimination throws autism being classed generally (ie unqualified) as a disability into doubt.

I find this rather confusing:

https://www.citizensadvice.org.uk/law-and-courts/discrimination/check-if-youre-protected-from-discrimination/what-counts-as-disability/

'The definition is set out in section 6 of the Equality Act 2010. It says you’re disabled if:

• you have a physical or mental impairment
• that impairment has a substantial and long-term adverse effect on your ability to carry out normal day-to-day activities'

Is it a variable thing then according to what you are trying use the disability definition to achieve?

Is this because we are on a spectrum with varying degrees of functionality?