A Buddha and a bodhisattva are related but not identical terms. A Buddha is fully awakened. A bodhisattva is a being oriented toward Buddhahood, especially through the cultivation of wisdom and compassion for the benefit of others. The details differ across Buddhist traditions.

What is a Buddha?
The title Buddha means “awakened one.” Gautama Buddha is the historical Buddha of the present age in Buddhist tradition.
Mahāyāna and Vajrayāna Buddhism also speak of many Buddhas, including Amitābha, Akṣobhya, and Vairocana.
What is a bodhisattva?
In early Buddhist usage, bodhisatta can refer to the Buddha in his previous lives and during the period before his awakening.
In Mahāyāna Buddhism, the bodhisattva ideal becomes a broad spiritual path: practitioners generate bodhicitta, aspire to Buddhahood, and cultivate compassion and wisdom for the benefit of all beings.
Famous bodhisattvas
Mahāyāna traditions revere figures such as Avalokiteśvara, Mañjuśrī, Kṣitigarbha, Samantabhadra, and Maitreya. Their stories and roles differ across texts and cultures.
Some advanced bodhisattvas are described with highly transcendent qualities, which can make the line between devotional categories seem less simple to outsiders.
When does a bodhisattva become a Buddha?
Within Mahāyāna path systems, Buddhahood is the culmination of the bodhisattva path. A bodhisattva is therefore not merely a compassionate person but someone whose path is oriented toward full awakening.
Different schools describe stages, vows, and cosmology in different ways.
Simple distinction
A Buddha has completed the path of awakening; a bodhisattva is on the path toward Buddhahood for the benefit of beings, especially in Mahāyāna Buddhism.