Short answers, pulled from the story.
Buddhist texts are collected in three main canons: the Pali Canon of the Theravada tradition, the Chinese Buddhist Canon of East Asian Buddhism, and the Tibetan Buddhist Canon of Indo-Tibetan Buddhism. There is no single textual collection shared by all of Buddhism.
The oldest surviving Buddhist manuscripts are the Gandharan Buddhist texts, found in Pakistan and written in Gandhari. They date from the first century BCE to the third century CE.
Buddhavacana means word of the Buddha, also called the dispensation of the Buddha or buddhanusasanam. It designates texts held to be in accord with the historical Buddha's teaching, the Dharma, though traditions differ on exactly which texts qualify.
The first surviving example of a printed text is a Buddhist charm, and the first full printed book is the Buddhist Diamond Sutra, dated to around 868. The first hand colored print, an illustration of the bodhisattva Guanyin, is dated to 947.
Abhidharma, called Abhidhamma in Pali, is an abstract and highly technical systematization of the doctrinal material found in the Buddhist sutras. Scholars generally date the canonical Abhidharma to around the third century BCE, after the Buddha's own lifetime, so it is treated as the work of later Buddhists rather than the Buddha himself.
Theravada Buddhism accepts the Pali Canon, or Tripitaka, as buddhavacana and rejects the Mahayana sutras outright, calling them Vedalla or Vetulla and counterfeit scriptures. Mahayana traditions instead argue that any well spoken teaching in accord with the Dharma counts as the Buddha's word, citing the Adhyasayasancodanasutra's line that all which is well-spoken is spoken by the Buddha.