The comparison of exterior and side tone of Persian and Arabic poems

The meaning of the exterior tone is rhythm and the side tone is rhyme. In Persian and Arabic prosodies, rhythm is defined as the equality of the place and the number of vowels and consonants. In other words, linguists called it vowel and consonant letters in two or more symmetrical order provided that they are not against frames and samples.
Rhyme means the repeated letters at the end of the words with different meaning that come at the end of the specific hemistich which specify the poetic frames of those hemistiches. Each pattern or sample that is used to make rhyme is called "Rokn". Because of the limitation of their numbers, some branches have been originated from them that are called "Zahaf" in Persian prosody and "Zahaf" and Cause in Arabic.
In Arabic, "Zahaf" is said to specific language rules that give more freedom to the poets in order to versify poems in every style, in comparison with them, Persian poets are not permitted to do so. Accordingly, it makes Arabic poems farther from the rhythm and tone. Persian poets are not permitted to violate from "Zahaf" except for limited occasions that are called rhythm in new prosodies. Persian rhyme has been extracted from Arabic rhyme.
However, according to Persian poems features, new rules have been considered which are more difficult to follow than Arabic rhyme.
Although there are some differences between Persian and Arabic rhyme and prosody, Persian literature pioneers have not found the requirements to invent new and separate samples and rules for it. Therefore, the terminologies of these two sciences and their applications have a lot of similarities.