Angular and data repository pattern

I've just finished the canonical Heroes tutorial and had a nose around, I'm not a web developer, so there may be something inherent in SPAs that I don't grasp.

Is there a data respository library for Angular/typescript I'm missing?

All the tutorials and walkthrough remind me of 1990s windows application where data is pulled from some database, and then operated on record by record.

In my backend world we would use DbSet<> or datasets and create a relational model, operate on it in locally and then "save" the changes.

Does such a thing exist in this world?...or is there something inherent that makes this pattern not apply?