Naive question: Is there a technical definition that differentiates a Seed round from Series A?

I used to think

- Seed round was raised from friends and family - but this one has tonnes of institutional investors.

- Seed rounds typically raise <1mm at <10mm valuation - but this one raised 6mm+ (at maybe 50-60mm valuation?)

- Seed rounds happen before the business is well defined - also not true in this case.

So why is this called a seed round and not a Series A?