Q&A: What you need to know about the worldwide cyber snarl

Flights were delayed. Court cases were postponed. Government computer systems were shut down. Even Starbuck’s beverage orders failed to register. It was a truly worldwide day of disconnections.

At the heart of Friday’s massive international technology disruption was CrowdStrike, a cybersecurity firm that provides software to scores of companies worldwide. The company says the problem occurred when a faulty update was pushed out to computers running Microsoft Windows for one of its tools...