Rabbi Solomon ben Isaac (or: Shlomo Yitzhaki) is known by the acronym: RaSh"I.
Rashi has been accepted by the entire Jewish world as the exegete par exellence, and he succeeded in completing commentaries to Judaism's most sacred texts, the Bible and the Babylonian Talmud. Rashi's commentary to the Torah was perhaps the first Hebrew book to be printed, and it is included in almost any edition of the Torah that is designed for traditional and synagogue use.
Rashi's commentary to the Torah is based on an intriguing combination of traditional and critical methods. In many instances he faithfully quotes the Talmudic interpretations of a particular verse,whereas in others he ignores them or explicitly rejects them in favour of more literal explanations. This apparent inconsistency has challenged subsequent students to seek an underlying system. Thus, it is widely argued that Rashi's main allegiance was to the plain meaning of the Bible, and utilized homiletical interpretations only in those cases where they provide a solution to a serious difficulty in the meaning of the text.
In citing traditional interpretations, he makes use of an impressive array of classical rabbinic literature, including the Targums (which provides him with an important instrument for translating obscure Hebrew words), homiletical and halakhic midrash, in addition to the Babylonian Talmud.
In some instances he translates Hebrew words into their French equivalents (which he calls "La'az"), providing posterity with some of the earliest records of medieval French dialects.
He frequently cites the lexicographic and grammatical works of the Spanish Jewish scholars Menahem ben Saruk and Dunash ben Labrat.
In general, Rashi demonstrates the kind of qualities that exemplify a master teacher. He is able to anticipate where students are likely to find difficulties, and provide explanations that are satisfying to both the beginner and the advanced scholar.