Buddha generally means 'Awakened Being', the being who has awakened from the sleep of ignorance, has attained nirvana and perceives things as they are. A Buddha is a person who has freed himself from all mental faults and obstructions and has attained nirvana or enlightenment. Many beings have become Buddhas in the past and many more will in the future.
The Buddhas help sentient beings in two ways: by imparting teachings and by blessing their minds. Without the blessings of the Buddhas it is impossible to generate a virtuous mind.