The growing demand for NFTs leads to a new, two-stage sales process. The basic idea is that the collection is offered first to a predetermined list of buyers through a "white list," and then to everyone else. Those stages are called Private sale (or pre-sale) and Public sale.
Whitelisted buyers get prior access to the collection and guaranteed purchase, as well as (usually) lower prices on NFTs. To get on the whitelist, a member must be active in the community or complete a number of tasks, such as inviting friends to participate in a sale, making posts on social media about the project, etc.