Core answer
Start here. This is the direct spoken answer to practice first.
Overview
Both can trigger validation, but they carry different semantics and interact with object and method validation differently.
@Valid is the Jakarta Validation marker commonly placed on a request-body, model, or request-part argument to validate that object and cascade into members also marked @Valid. Spring's @Validated can trigger the same object validation and additionally select validation groups. Constraints directly on controller parameters or return values require method validation rather than only object validation. The resulting exception can differ depending on whether one argument or the whole handler method is validated.