Stock trading refers to buying and selling shares or stocks in publicly-traded companies. It is a form of investment where individuals or institutions purchase an ownership stake in a company, hoping that the value of their shares will increase over time. Stock trading can be done through various platforms such as stock exchanges, brokerages firms, and online trading accounts. The goal of stock trading is to make profits by buying undervalued stocks and selling them when they reach their full potential or by holding onto the stocks for long-term capital appreciation.