Cumulative preferred shares and non-cumulative preferred shares are two types of preferred stocks that differ in terms of their dividend payment structure.

Cumulative preferred shares guarantee that any missed dividend payments will accumulate and be paid to shareholders in the future before any dividends are paid to common shareholders. In contrast, non-cumulative preferred shares do not accumulate any missed dividend payments and the company is not obligated to pay them in the future.

The main benefit of cumulative preferred shares is that they offer more security to investors since they ensure that missed dividend payments will eventually be paid. On the other hand, non-cumulative preferred shares typically offer higher dividend rates and may be more attractive to investors seeking higher returns. Ultimately, the choice between these two types of preferred shares depends on an investor's risk tolerance and investment goals.