Fluent Bit is a log collector that can be used with New Relic Logs for Kubernetes to collect cluster log data, and it allows developers to control which logs are collected by using two different strategies: editing the parser configuration or using Kubernetes annotations. The second strategy, using annotations, provides more flexibility and decentralization of the logging configuration, allowing developers to adjust their logging needs as they add new pods to a cluster. By enabling New Relic Logs for Kubernetes and choosing one of these strategies, developers can get what they need from the logs while also optimizing costs by not sending unnecessary data.