A Form 8-K is the SEC filing public companies use to disclose material events — a major acquisition, executive departure, earnings release, restructuring, or other significant development — on a current basis, typically within four business days. It is a primary mechanism for satisfying Reg FD's broad-disclosure requirement. For communications teams, the 8-K and the press release are coordinated instruments: the filing satisfies the regulator, the release shapes the narrative for market and media.