Ulama are educated in religious institutions.They have strong knowledge about Islamic doctrine and law.The Quran and Hadith are the holy books from where they get knowledge.
It is mentioned that those who doesnot loves or respect Ulemas are not a true Muslim.
Ulemas are the Islamic Scholar who study for 10 to 12 years in Madarsas(School), day and night to acquire the knowledge of Islam.
It is also mentioned that, they are like stars in the sky.The death of one ulema is like the death of 1000 ordinary Muslim.
Devils(Shaitan) can not divert Ulemas from right path, as ulemas has a knowledge of right and wrong.
Ulemas who are Mufti has a right to give fatwa(a discision on point of Islam).