Buddha is the universal truth, and Buddhism is the path to realise it. Buddha is our true nature, openness clarity sensitivity, the enlightened state of the universe. Everything we experience is simply a manifestation of this true nature. If we can realise this nature, vast, ultimate peace, then we are Buddha. Buddhism is the path to realise Buddhahood, and it is also the teaching that inspires us to that realisation.
In order to realise our true nature, we must follow a guide. Whether our guide is a book or not, the words originated from a teacher. It is important that the teacher we follow has been entrusted to do so by their teachers and so on down the line. This is what we mean by lineage, an unbroken succession of authorised lineage-holders empowered to pass on the essence of the teachings to the next generation. In this way we can trace back a true lineage to the first Buddha of this world era, Sakyamuni.
(for more information please see Early Lineage Figures and Recent Lineage Figures)