Like debt has fixed interest rate, preference shares have fixed dividend and they also have a preference of payment at the time of liquidation just as debt holders get. They do not have any say in the management in the form of voting rights also do not have any share in the residual profits also.
Certain attributes of preference shares resemble the equity shares.
The preference dividend is also paid out of net profits after taxes but the only difference is that the dividend is fixed. In the weak financial situations, management may consider not paying the dividend to preference shareholders. If the shares are cumulative preference shares, the said dividend may be postponed but will have to pay if the next year financials are good. A specific type of preference share i.e. irredeemable preference share does not have a certain maturity also.
These are a different type of debentures which are also categorized as hybrid financing. In addition to the normal debenture features, these debentures have the option to convert the debenture into equity on certain terms and conditions.
These debenture holders enjoy the regular income of interest till the time they exercise their right or the option of converting it into equity shares.
Similar to debentures, warrants also have the right to purchase equity shares of a company. Warrants are not a debenture or equity till the time they are exercised and equity is purchased. They are just a right or option to purchase equity which the holder has.
There are debt instruments which accompany options that may be either call or put. These options convert the debt into equity. This kind of instruments remains debt at the time of issue until the time they are exercised. The post they are exercised, they become equity. A call option allows the holder of the option to buy something at a certain price and on or before a certain date whereas put option allows selling.