THE QUESTION IS WHAT ARE THE DIFFERENCE TYPE OF MADDI AND THEIR USAGE

Question
THE QUESTION IS WHAT ARE THE DIFFERENCE TYPE OF MADDI AND THEIR USAGE

Answer
The lessons on the mudood (plural of medd) can be found starting at the following link:
http://www.abouttajweed.com/index.php/tajweed-rules/49-the-mudood-the-lengthenings/101-the-mudood-lengthenings-part-1
Then you can click on the word "next" to follow it.  There are ten lessons on the mudood but more than ten types of medd. 
Their use is for applying recitation of the Qur'an at is was revealed.