Yes, the order has a specific list.

EDIT: Here is the order.

https://www.governor.ny.gov/news/no-2026-continuing-temporar...

> Any essential business or entity providing essential services or functions shall not be subject to the in-person restrictions. This includes essential health care operations including research and laboratory services; essential infrastructure including utilities, telecommunication, airports and transportation infrastructure; essential manufacturing, including food processing and pharmaceuticals; essential retail including grocery stores and pharmacies; essential services including trash collection, mail, and shipping services; news media; banks and related financial institutions; providers of basic necessities to economically disadvantaged populations; construction; vendors of essential services necessary to maintain the safety, sanitation and essential operations of residences or other essential businesses; vendors that provide essential services or products, including logistics and technology support, child care and services needed to ensure the continuing operation of government agencies and provide for the health, safety and welfare of the public;

I watched the press conference and he said that they'd have a list later this afternoon. Food delivery is essential. One of the reporters asked if IT support (actually Best Buy's "Geek Squad") was essential, and he said he didn't know.

My impression is that "essential" is very liberal right now.

Usually defined by each company for each position.