Voting basis refers to what number or percentage of votes are required for a proposal to be adopted, or for a candidate to be elected. Two elements make up a voting basis: the proportion that must agree (majority, two-thirds, three-quarters, etc.) and the set of members to which the proportion applies (e.g. the members present and voting; the members present; the entire membership of the organization; the entire electorate etc.)

Voting bases include simple "majority"

Plurality voting system

The plurality voting system is a single-winner voting system often used to elect executive officers or to elect members of a legislative assembly which is based on single-member constituencies...

 or "first past the post" (the largest number of votes, even if less than fifty percent), absolute majority (over fifty percent), and supermajority

Supermajority

A supermajority or a qualified majority is a requirement for a proposal to gain a specified level or type of support which exceeds a simple majority . In some jurisdictions, for example, parliamentary procedure requires that any action that may alter the rights of the minority has a supermajority...

(the proportion required is greater than fifty percent, e.g. two-thirds).