In Salesforce B2C Commerce, the Logger class provides several methods for different levels of logging severity: debug, info, warn, error, and fatal. The method Logger.error() is used to record error-level messages, which indicate significant issues that a developer needs to address. This is appropriate for scenarios like the one described where a payment instrument cannot be found, potentially affecting the order processing. Using Logger.error() ensures that these logs are recorded with an appropriate severity level, making them easier to identify and respond to during debugging and monitoring.