What is the differences of Mecca?

It would be more appropriate to title this question as "SPECIALITIES OF HARAM AL-SHARIF" rather than "Specialities of Mecca". Mecca hasn't been different as a city, it has been different because Allah have made it haram, that is, it has become HARAM AL-SHARIF. The main fiqh features of the Haram region can be listed as follows:

1. It is not permissible for non-Muslims to enter the Haram.

2. It is not allowed to enter the Haram without an ihram.

3. The reward of a prayer performed there is written as a hundred thousand folds.

4. It is possible to perform prayers there at the time of karaha.

5. Its plant cannot be plucked, its prey cannot be hunted.

6. It is forbidden to fight there.

7. The punishment for the murder committed there was more severe.

8. What is found cannot be retrieved.

Although there are some differences in details among scholars, these are the basic fiqh rules for the Haram region.