Shura is consultation, and as an institution it is the Islamic principle that legitimate authority takes counsel rather than deciding alone.
A Quranic instruction
The word is Quranic: one verse instructs the Prophet to consult his followers in affairs, and another describes the believers as those who conduct their affairs by mutual consultation, and from these the tradition derives a general principle that rule should be exercised with counsel. In the early community the choice of a successor to the Prophet was framed in terms of consultation among the leading Companions, and the idea of a consultative body, the ahl al-shura, those qualified to advise and to ratify, entered classical political thought as a mark of rightly ordered authority.
An old word in modern argument
Because the sources commend consultation without specifying its machinery, shura has been available to very different modern programmes. Reformers have read it as an Islamic warrant for representative and constitutional government, arguing that consultation implies accountability, while others have kept it advisory, a duty to seek counsel that leaves the final decision with the ruler. Modern states across the Muslim world have named consultative councils shura, with powers ranging from the merely advisory to the substantial, so a single Quranic term now labels institutions that differ sharply in how much authority they actually hold.