What is a “divisional”?
When you file a patent application, you pay the Patent Office a fee to search patentability on a single invention. If the Patent Office decides your claims are directed to multiple inventions, the office will require that you choose which of the different inventions you want to proceed with.
Claims to the other inventions are not necessarily lost; they can be pursued in child applications called divisionals.
One worry is that if the original application is abandoned, or matures into an issued patent before a child application is filed, you lose the rights to pursue the non-selected inventions.
But not to worry. Filing a child application entails little more than paying additional fees.
Yes, the child applications cost more money, but one benefit is that you likely end up with multiple patents, and broader coverage.
Another benefit is that the divisional gets a priority date all the way back to the parents priority date.
In a system where the first to file is the rule, the ability to claim a right back to the original filing date is an advantage.