What is grand chapter in a sorority?

In a sorority, the Grand Chapter is the highest governing body of the national organization. It's essentially the sorority's national board of directors. The Grand Chapter is responsible for setting national policies, overseeing the operations of all chapters, amending the national constitution and bylaws, and generally ensuring the consistent application of sorority values and standards across all its collegiate and alumnae chapters. Its members are typically elected or appointed officers and representatives from various chapters.