I thought it was all PLA:

https://en.wikipedia.org/wiki/Ingeo

I think there's also "biodegradable" plastic which has cornstarch in it which allows bacteria to degrade it, but that's not the same thing?

PLA doesn't actually biodegrade outside of specialist industrial facilities, it was much vaunted as an eco friendly thing when 3d printing started using it, but we rapidly found out it can last decades without breaking down much if at all.