I am new to Svelte and have noticed that some elements in the SSR code generated by Svelte include a special data-svelte-h attribute on them, mostly static elements but I can’t seem to find a pattern.

What is the purpose of this attribute and how exactly does it help in hydration?

For example, how does it work internally, for e.g. does it compute the hash of the internal contents of the element on the server and then have that hash as its value in the rendered HTML code and then checked again on the client side?