Final answer:
An investor buys a share of a company when they purchase stock, becoming one of many shareholders. This ownership stake grants them certain rights, such as voting on company matters, but does not amount to full ownership, especially in large companies with many shareholders.
Step-by-step explanation:
When an investor buys stock in a company, they are purchasing a share of that company. This makes them one of the many shareholders and gives them a slice of the ownership. Stock represents ownership within the firm, with the amount of influence directly correlated to the amount of stock owned. For instance, corporate giants like IBM, AT&T, Ford, and General Electric have millions of shares. Being a shareholder also grants the investor the right to vote on important company matters, such as electing the board of directors. However, in large companies, no single investor usually holds a majority of the stock, signifying that individual control is limited.