Are Vajrayana and Tibetan Buddhism the same thing?
No they are not the same, Tibetan Buddhism is a broader concept that subsumes Tibetan Vajrayana. Also, there's non-Tibetan Vajrayana, some still practiced in e.g. Japan. 

To some degree all schools of Tibetan Buddhism, and particularly Karma Kagyu, recognize three yanas (Hinayana, Mahayana and Vajrayana) as subsequent stages on an individual's path to complete enlightenment. These days many teachers tend to have their student jump straight into tantra right after Ngondro (preliminary stage of Vajrayana training), but traditionally, the student is supposed to master the foundational theory, discipline, and meditation of Hinayana before proceeding to Mahayana, then master Mahayana's practice of subverting one's ego, and attain realization of nonconceptual emptiness, and only then proceed to tantric practices of working with Yidams (generation/completion), the Vajrayana proper.