Startups are segregated into following stages based on product lifecycle

Nascent/Seed

In its product ideation and concept stage.

Prototype may or may not be available.

Early/Growth

Product has entered the market and modifications are being made based on customer/market feedback.

Customer acquisition in progress and has a steady source of income.

Expansion

Company is well established in the market space and there is a rapid growth in revenues.

Potential to scale the business is being tapped into and attempts are being made to increase the customer base substantially.

Mezzanine

Product has made it on a commercial basis.

New products/competitor products are being acquired. Expansion into other markets is being made.