Where does the Anonymous ID saved on the database when being generated and sent to the browser?

Hi, 
OptiDict supports the anonymous flow. I'm creating a new anonymous token using the /token/anonymous endpoint using the anonymous ID that is generated by Optimziely. Now I would like to know if that generated anonymous ID that I'm using to generate a token is saved somewhere on the database. I was able to find the anonymous ID when creating a cart with that anonymous id. However, what I would like to know if it's saved somewhere on the database before creating a cart. Specfically when the anonymous ID is being generated.

Any help is appreciated.