Brahmavihara means "divine abidings" and refers to four formal mediation practices:

• loving-kindness aka metta
• compassion aka karuna
• sympathetic joy aka mudita
• equanimity aka upekkha

In each of these practices, one uses repeated phrases to evoke the basic feeling of the practice, possibly extending the feeling to various categories of people, beings, directions, etc., or may just tune into the feeling itself.

Technically, these are samatha practices, meaning concentration practices, as they develop samatha jhanas using the various feeling as a base.

-Daniel Ingram