What is storage mass in a Kaspa transaction?

Storage mass is a specific measurement that captures a transaction's storage mass commitment on the Kaspa network. Kaspa's Toccata release introduced multiple distinct mass concepts — storage mass, compute mass, and transient mass — each tracking a different kind of resource a transaction consumes. The field that previously used the generic name 'mass' was renamed 'storageMass' in JSON and JavaScript APIs (and 'storage_mass' in Rust and protobuf APIs) precisely to make clear which type of mass it represents and to avoid confusion with the newer concepts. For a beginner, this matters because it shows that Kaspa accounts for different resource types separately, giving the network a more precise way to measure and validate what each transaction demands.