Yoga means linking with the Supreme. The Bhagavad-gita (Chapter 6, verses 1-47) describes the yoga system in detail. Various yoga systems exist (karma-yoga, jnana-yoga, dhyana-yoga, bhakti-yoga), but all aim at the same goal. The Bhagavad-gita (12.2-5) teaches that the highest yoga is bhakti-yoga, devotional service, because it directly engages one with the Supreme. Meditation should focus on the Supreme Person, and bhakti-yoga is the most direct path.