Hi, this is the simplest explanation that I found on the net:
Arabic itself is commonly sub-classified as Classical Arabic, Eastern Arabic, Western Arabic, and Maltese. A modernized form of Classical Arabic exists and is referred to as Modern Standard Arabic (MSA). Classical Arabic, which is the language of the Qur'an, was originally the dialect of Mecca in what is now Saudi Arabia. An adapted form of this, known as Modern Standard Arabic, is used in books, newspapers, on television and radio, and is also the common conversational language between educated Arabs from different countries.
Egyptian Arabic is part of the Eastern Arabic subclass, which includes the Arabic dialects spoken in a large region of North Africa (Egypt and Sudan), the Middle East (Syria, Iraq, and the Arabian Peninsula), and Arabic countries in Asia. Eastern Arabic, in addition to Egyptian Arabic, includes Levantine Arabic, spoken in Lebanon, Syria, Israel, and Palestine, and Gulf Arabic as well as dialects in adjacent regions.