Short answers, pulled from the story.
Computer security is a subdiscipline of information security focused on protecting software, systems, and networks from unauthorized disclosure, theft, damage, disruption, or misdirection. It matters because modern societies depend on computer systems to run power grids, financial markets, electoral processes, healthcare, and aviation, making breaches potentially catastrophic.
It is estimated that more than 90% of security incidents and breaches involve some kind of human error. The Verizon Data Breach Investigations Report 2020, which examined 3,950 breaches, found that 30% of cybersecurity incidents involved internal actors within a company.
The first internet computer worm was released on the 2nd of November 1988 by Robert Tappan Morris, a 23-year-old Cornell University graduate student. Morris said he wanted to count how many machines were connected to the Internet, but the worm spread uncontrollably and slowed down thousands of computers.
The Stuxnet worm, discovered around 2010, reportedly destroyed almost one-fifth of Iran's nuclear centrifuges by disrupting the industrial programmable logic controllers inside the facility. It is generally believed to have been launched by Israel and the United States, though neither has publicly admitted this.
In early 2016, the FBI reported that business email compromise scams had cost US businesses more than $2 billion in approximately two years. These scams typically involve attackers impersonating executives to trick finance staff into transferring funds or handing over sensitive records.
In April 2015, the Office of Personnel Management discovered a breach that resulted in the theft of approximately 21.5 million personnel records. The stolen data included Social Security numbers, names, dates and places of birth, addresses, and fingerprints of current and former government employees and anyone who had undergone a government background check. Federal officials described it as among the largest breaches of government data in US history.