What's in a letter? If it's the ABC, not much. But if it's the Alef-Bais (the Hebrew Alphabet), well, that's a whole different matter. Each letter has myriads of meanings, many of which are appealingly presented by Rabbi Mordechai Zev Nemtzov in his lively book, The ARTiculated Alef-Bais. They have simple meanings. The Gimmel, third letter of the alphabet, means to give, while the following letter, the Dalet, means poor, implying that G-d created the rich to assist the poor. The letters also have deep Kabbalistic secrets. Take the Yud, the tenth letter of the Alef-Bais. The small, simple point of the Yud represents the G-dly spark in every Jew that can never be extinguished. It is also the only letter suspended in the air, implying that the focus of a Jew be on more than just acquiring earthly objects, but on attaining spiritual eternity. On yet a whole other level, each letter has a numerical value. Here is where the author, who has a flair for math, really gets going. He finds connections between, for instance, the letter Tav equaling 400 and the 400 pieces of silver with which the patriarch Abraham bought the Cave of Machpela as a burial plot. The high point of the book, however, is the vibrant, colorful illustrations that capture the personality of each letter. There's much to look at and lots to learn here for both young and old.