Bodhi tree is usually translated as Enlightenment Tree. Bodhi or ‘Enlightenment’ here refers to the Path-Fruition Knowledges, Omniscient Knowledge, Nibbana. We can say that Bodhi tree ‘is the tree under which the Buddha gained enlightenment’. Therefore the Bodhi Tree is a remembrance of the Buddha’s enlightenment. It is a symbol of the Enlightenment of the Buddha.
When we do Puja or offerings & chanting at the Bodhi Tree we are also respecting the Buddha’s enlightenment. We get joy and happiness, which can produce merits. These merits support our practice.