In the Buddhist context meditation is a means to transform our disturbing emotions into their essence. The methods are manifold and also differ in the Three Yanas of the Buddhadharma, all stemming from Buddha himself.
The aim of the Hinayana is to attain liberation for oneself from suffering while the Mahayana and Vajrayana base on the firm resolution of the practitioner to take all beings as their family, hence taking the vow to actually lead all the new family members to final enlightenment, not giving up until this aim will be attained.
The basis for Mahayana is the Hinayana, and the basis for Vajryana arr both Hinayana and Mahayana together, paired with the special methods and particular view of the Vajrayana.
In Mahamudra Ocean of Certainty, practitioners are being step by step led through all the above steps by the master, starting with refuge.