What are dividend reinvestment plans, and what benefits do they offer to investors? Are there any disadvantages?

Question:

What are reinvestment plans, and what benefits do they offer to investors? Are there any disadvantages?
Dividend
A dividend is a distribution of a portion of company’s earnings, decided and managed by the company’s board of directors, and paid to the shareholders. Dividends are given on the shares. It is a token reward paid to the shareholders for their...