Query Builder builds SQL-oriented queries and normally returns generic result objects, arrays, counts, or scalar values. It offers a lightweight fluent API and is often a good fit for aggregate reports, joins, bulk updates, or queries that do not represent one domain model.

Eloquent is Laravel’s ORM and maps rows to model objects. It adds relationships, attribute casting, accessors, mutators, scopes, events, factories, and convenient persistence methods. Eloquent is usually clearer for model-centric business logic, while Query Builder may be preferable when its simpler abstraction or more direct SQL shape is a better fit.