Short answers, pulled from the story.
The Arabic word sharī'ah means way or path and refers to religious regulations governing the lives of Muslims. Early scholars traced this term to a pastoral image of watering animals at a permanent water-hole where reaching that source was essential for survival.
Traditional theory recognizes the Quran, sunnah, ijma, and qiyas as the four sources for sharia. The Quran is considered the most sacred source while hadith provides more detailed legal guidance than the Quran itself.
The main Sunni schools emerged in the ninth and tenth centuries including the Hanafi, Maliki, Shafi'i, and Hanbali madhhabs. By the twelfth century almost all jurists aligned themselves with a particular madhhab.
Hadd applies to punishments ranging from public lashing to death for limited crimes such as murder adultery slander theft and hirabah. Qisas refers to retaliation in kind where Sharia specifies equal retaliation or monetary compensation called diya instead.
Sharia was traditionally interpreted by muftis who were private legal specialists issuing fatwas generally free of charge in response to questions from laypersons. From 12th century onward Muslim rulers began appointing salaried muftis who were gradually incorporated into state bureaucracies.