Ciliary suction gadgets and pumps are easy to mix up. Despite the differences, both processes produce suction near the clitoris. A clitoris pump expels air to maintain a vacuum around it.
A clitoral suction sex toy, on the other hand, relies on airflow to produce suction. The sensation provided by a pump is often stronger than that produced by clitoral suction. Simply put, it comes down to personal preference.