AOA is one of the most important parameters for understanding airplane performance and handling (see What Is Angle of Attack?) because a typical wing has a limited range of angles of attack over which it can function efficiently. In its simplest form, lift is a function of speed, air density, wing area, and AOA.
Day trading is speculation in securities, specifically buying and selling financial instruments within the same trading day. Strictly, day trading is trading only within a day, such that all positions are closed before the market closes for the trading day. Many traders may not be so strict or may have day trading as one component of an overall strategy. Traders who participate in day trading are called day traders.
Day traders do not invest. Day traders sit in front of computer screens and look for a stock that is either moving up or down in value. They want to ride the momentum of the stock and get out of the stock before it changes course.