Svelte 5 runes are Svelte-specific syntax for the generic idea of JS signals such as found in SolidJS. Svelte runes are effectively compiler keywords.
Broadly speaking, runes are aiming to be higher level (e.g. pretty syntax to help developers declare state) whereas signals are lower level (e.g. how internal implement state dependencies).
Svelte runes, as a concept, are somewhat contentious among some developers. This is because runes make Svelte feel more like React or Vue, yet feel less simple. My opinion is that runes are a good/necessary step for building larger apps, even though it makes it a bit harder for novices.
