A server baseline is a set of metrics that represents the normal performance and behavior of a server under a specific workload and configuration. A server baseline can help answer the server performance question by comparing the current performance with the previous performance before the upgrade. This can help identify any changes or issues that may have affected the server performance.

The per-concurrent user licensing model is a type of licensing model that restricts the number of active sessions or connections to a software application at any given time. This means that multiple users can share the same license, as long as they do not access the application simultaneously. This model is often used for applications that are accessed intermittently or for a short duration by different users, such as remote access software, web-based applications, or testing tools.

The company encrypted data "at rest", so they need to encrypt data "in transit".

The user has likely fallen victim to a phishing scam, which is a fraudulent attempt to obtain sensitive information, such as passwords, by disguising as a legitimate entity. The link in the email that required the user to change the account password was probably a fake website that mimicked the company's external database, and captured the user's credentials when they entered them. This could compromise the security and integrity of the company's data, as well as the user's identity and privacy.
The company should take immediate action to prevent further damage and investigate the incident. The first step is to disable the user's account and inform the security team. Disabling the user's account can prevent unauthorized access to the external database by the attackers, who may use the stolen credentials to log in and manipulate or steal data. Informing the security team can alert them of the breach and allow them to take appropriate measures, such as scanning for malware, changing passwords, notifying other users, and reporting the incident.