The root word of ijtehad is “Juhd” which means “to try or strive”. It's the process in which a scholar independently strive to find answers, reasons or solutions to the problem in light of Quran and Ahadees. Qiyaas Sometimes they use analogy to find solutions. E.g: alcohol is forbidden. So if a thing has same effect as alcohol, it is also forbidden. This method of analogy is called “Qiyaas”.