Rum is made from either pure cane syrup or the molasses byproduct of making cane syrup. Rum (Rhum) agricole is made from cane syrup, the fresh juice of the cane pressing. Rum Industriel is made from the byproduct of making cane syrup -- molasses.
Rums made from pure cane syrup have more natural flavor.
From there, rum is aged like tequila. Silver is unaged. It is strong and raw. Gold is aged for a short time.
Then the finer rums are aged for longer, often using oak bourbon, brandy, sherry, or other barrels to enhance flavor. These are sipping rums. They are quite fine, smooth, and flavorful.
A rum does not need to be made by a distiller. A company can buy a batch and blend it, age it, and market it.
Most whiskeys are blends, even from different distilleries within and without a particular company.