The book sacred to Christians, which they consider to be the inspired word of God. The Bible includes the Old Testament, which contains the sacred books of the Jews, and the New Testament, which begins with the birth of Jesus.
Thirty-nine books of the Old Testament are accepted as part of the Bible by Christians and Jews alike. Some Christians consider several books of the Old Testament, such as Judith, I and II Maccabees, and Ecclesiasticus, to be part of the Bible also, whereas other Christians, and Jews, call these the Old Testament Apocrypha. Christians are united in their acceptance of the twenty-seven books of the New Testament; Jews do not consider the writings of the New Testament inspired. The Bible is also called “the Book” (bible means “book”).
Note: By extension, any book considered an infallible or very reliable guide to some activity may be called a “bible.”