A split ring and a jump ring are both metal rings used in jewelry-making. The main difference is that a split ring is a more secure and permanent option for attaching items to jewelry or other objects, while a jump ring is a more flexible and temporary option. Split rings consist of two coils of wire that are tightly wound together, which makes them much less likely to come apart than a jump ring, which is a single ring that can be opened and closed with pliers.

Because of their secure design, split rings are often used to attach items to keychains, cell phone cases, and other objects that will be subjected to frequent use and handling. They are also commonly used in jewelry-making to attach charms, pendants, and other components to necklaces, bracelets, and other items.

Jump rings, on the other hand, are often used in jewelry-making to connect chains, links, and other components together. They are a more flexible option because they can be easily opened and closed using two chain nose pliers, which allows for more design options and easier customization.

Overall, the choice between a split ring and a jump ring depends on the specific application and the level of security and flexibility required for the project.