What is 'Corporate Governance law' ?

From the website of law firm Weil, Gotshal and Manges, awarded the title of 'Global Corporate Governance law firm of the year' both in 2005 and 2006 by Who's Who Legal:

Weil Gotshal's Securities/Corporate Governance Litigation practice addresses the increasingly complex web of federal and state statutes, rules, common law and regulatory oversight of public and private organizations, from both the litigation and counseling perspectives.
This practice includes not only class action, "mass action," bankruptcy and other private litigation, but also civil regulatory and criminal proceedings under federal and state securities laws; shareholder derivative and other corporate/partnership governance and fiduciary duty disputes; and litigation involving complex corporate transactions.
Equally important, the other focus of this practice involves counseling issuers, boards of directors, audit committees, and other standing or special board committees and significant shareholder or securities industry constituencies, on issues involving disclosure and other securities law compliance and on issues of corporate governance (including internal investigations) and fiduciary duties under state and federal law.