Learn in the textbookOrganizational Structure for Promoting Security
DefinitionA CSIRT (Computer Security Incident Response Team, read "see-sert" in Japanese) is a specialist team that investigates the cause, contains the damage and restores systems when a security incident (インシデント) occurs.
ExplanationThe full name is Computer Security Incident Response Team, and an incident here means any accident or event that undermines information security, such as unauthorized access or a malware infection. The CSIRT serves as the contact point for reports from inside and outside the company and leads incident response within the organization. It can be a permanent team, or it can be assembled from the relevant departments each time an incident occurs.
AnalogyIt is like a hospital's emergency team. When a patient is rushed in, they assess the condition and treat it, and once things settle down they look into the cause and advise on how to keep it from happening again.
Memory hookIn Japanese it is read "see-sert". The IRT at the end stands for Incident Response Team, so the name itself says "the team that responds to incidents".