Preferred Stock is a type of stock in a corporation that has preferential terms, rights, and privileges as compared to Common Stock. The Preferred Stock Liquidation Preference is one of the primary features of Preferred Stock that makes it “Preferred.”
The Preferred Stock is organized in one or more “Series,” the first of which is often named Series A or Series Seed. Later rounds of financing will be named sequentially – Series B, C, D, etc.
If there are SAFEs or convertible notes converting into shares of Preferred Stock, the security issued upon such conversion might be a “Shadow Series” of Preferred Stock (e.g. Series A-2 Preferred Stock) instead.