But, both churches, regardless of the wording or the legal nicities, teach that the substance in the bread and wine is changed or alterered living flesh and blood of Jesus -- whose appearance and taste is altered to make it palatable.
The difference between the Catholic and Orthodox teachings is in line with their approach to theology: the Catholic Church developed a philosophical dogma, based on the original Church teachings, trying to "explain" this miracle, magic, whatever you want to call it, while the Orthodox Church continues to use the traditional approach of the original Church by simply calling it a "mystery" that is beyond our comprehension.