DatoCMS client vs GraphQL schema directly

What are the advantages of using the DatoCMS client over straight graphql schemas?
Are there extra things that the client does?

By client you mean the datocms-client NPM package right?

Thatโ€™s a client for the REST Content Management API. For the GraphQL Content Delivery API thereโ€™s no client, itโ€™s just GraphQL

That clarifies things.
Thanks!