Can testing be considered a process of verifying correctness and compliance of a software product with requirements, or does it also include processes of their validation?

Testing is not only the process of verifying the correctness and compliance of a software product with requirements, but also the process of their validation.

Verification answers the question of whether the requirements are correctly implemented (i.e., whether the product meets the specifications). Validation answers the question of whether the product meets the expectations and needs of the user.

Thus, testing includes both aspects: verifying the correctness of implementation and confirming that the product solves the set tasks.