Faith is the logical deduction of reason that forms trust in the truth of the buddha's teachings. Because we find some truth and merit to what the buddha is saying, we listen, study, and practice. Because we do not fully understanding all of what the buddha is saying yet, we use this initial logic and rationalization as a trust and faith that the buddha is right.
So in Buddhism, we practice and cultivate, and that becomes the concrete proof/evidence of the truth in the buddha's teachings. That proof reinforces our faith and motivation to continue listening to the buddha and practicing more of the buddha dharma.
The faith in Buddhism is not blind because we can prove everything to ourselves. We can find the answers to our faith, as opposed to a heavy-faith-based religion such as Christianity. You can't really prove that God is your omnipotent creator, the meaning of life, the source of your nature, that God manages our destinies and affairs, cause/effect/retribution is God's will, God's heaven, the salvation by Jesus, etc. In Christianity, you die in hopes that you were right. Whereas in Buddhism, that faith is practiced and proven over time.
For example, the fundamental aspects of how we came to be, is understood and discovered over time as we study and practice more. As we progress, we start to see how this world really works, mechanically. In Christianity, it's a blind race to the finish line for that topic.
If your question was actually more superficial, then I'll re-answer it here:
People bow to the Buddhas and Bodhisattvas out of respect, gratitude, and dedication to the Buddha Dharma. They practice and cultivate the nature of giving and humility by making offerings of fruits, vegetables, incense, to the buddhas. Simply put, it's paying respects to someone you look up to.
Venerating and paying respects to the buddhas is a way to tune your nature back to the buddhas. Gazing upon the buddhas is like looking at your final destination. Seeing the accomplished ones... we renew our motivation and dedication. The practice of veneration also creates affinities and memories with the buddhas so that in the future, the buddha dharma will always be close to you. You'll always find the buddha dharma again and never steer far from it.
Buddhas and Bodhisattvas cultivated in which their abilities are inconceivable. They vowed in the past to relieve countless difficulties and sufferings of living beings. So that is why the Buddha told us about many other buddhas and bodhisattvas and their specific vows that serve as functions. So people in Buddhism often look to the buddhas and bodhisattvas for help and guidance in affairs and matters that are out of their control. Their sincerity brings forth a mind and heart of faith and trust. And when those extraordinary responses take effect, that person's faith skyrockets and they end up listening to the dharma and practicing the dharma even more.