What is a blue team?
Blue team is an specialized group of cybersecurity professionals, experts in threats identification, cybersecurity incidents analysis, remediation and forensics.
As opposed to the red team, blue team has to identify, detect and prevent cyberattacks. Usually they work inside a SOC (Security Operations Center) in 24x7 shifts. They constantly monitor SIEM and other sources of information to detect any anomaly and respond proactively.