What is the difference between a procedural language and declarative language?

Procedural is nothing but just using procedures to instrct te machine. The procedures provides a level of abstraction here.

Declarative means to program without specifying the steps involved clearly. It allows us not give the control flow.

ex - SQL is declarative as it does not need the control flow to be implemented.

SQL is also procedural as it works on procedure names that are predefined.