A more thorough explanation:

Form 8-K is a report that public companies file with the Securities and Exchange Commission (SEC) to disclose important changes. Unlike other reports that are filed annually or quarterly, a company files a Form 8-K whenever a significant event happens. This makes the Form 8-K one of the most commonly filed SEC forms.

The SEC Form 8-K Instructions state that a public company must file a Form 8-K when certain events occur. These events include:

• Entering into or ending a significant agreement
• Bankruptcy
• Completing an acquisition or sale of assets
• Changes in financial condition or results of operations
• Unregistered sales of equity securities
• Changes in the company's certifying accountant
• Changes in control of the company
• Changes in or election of directors and officers
• Amendments to articles of incorporation or bylaws
• Submitting matters to a vote of security holders
• Regulation FD disclosure
• Financial statements and exhibits

For example, if a company completes a significant acquisition, it must file a Form 8-K to disclose the details of the acquisition. Similarly, if a company's financial condition changes significantly, it must file a Form 8-K to disclose the change.

Overall, the Form 8-K is an important tool for investors and the public to stay informed about significant events that affect public companies.