It is very important to begin by stipulating the fundamental timing demarcating factor between the Makkan and Madinite surahs. It is such that the Makkan surahs are those from the Qur'an that have been revealed before the Hijrah of the Messenger (PBUH) to Madinah excluding the verses revealed in Makkah after the Hijrah. And the Madinite are those from the Qur'aan that were revealed after the Hijrah including those which were revealed in Makkah (after the Hijrah).
However, there is another demarcation based on the place consideration which states that the Makkan surahs are the Ayats revealed in Makkah including those revealed after the Hijrah. And the Madanite are those that were revealed in Madinah. And it gets in Makkah and its boundaries.
A third view states that the Makkan surahs are those that talk about the people of Makkah, while the Madinite are those that talk about the people of Madinah. This understanding takes into consideration the addressee.
The problems that emanate from the first and second lead to a serious confusion in the exact margins separating the two sets of revealed surahs. In both cases, there will be so many instances whereby a surah is slit into part Madani and part Makki and even a times more, especially when the verses of such surahs have been revealed in different places that may even be outside Madinah and Makkah like Badr etc.
Based on this fact, the first opinion based on timing factor is considered best in distinguishing between the Makkan and Madinite surahs.
Nonetheless, some of the commonest features of the Madinite surahs are summarily as follow:
1- The Madinite surahs are often addressed to the believers with the introduction Yaa ayyuhallathiina aa'manuu - "O you who believe!"
2- They are mostly of a legislative nature and it is true to say that the laws of Islam (the shari'ah) are found principally in the passages dating from the prophet's migration to Madinah.
3- They are generally longer than the Makkan surahs.
4- Those parts of the Qur'an belonging to the Medinite years are predominantly on legal, social and political issues.
5- The private life of the Prophet (PBUH) is more in the Madinite surahs. In the Makkan surahs, the speech could be directed to him (PBUH) but the message is usually for the general public or not for him as an individual, while Madinite focus on him as an individual.