The blog post discusses the migration process to the Elastic Common Schema (ECS) within Beats environments, following the introduction of ECS in February 2019. ECS standardizes field names and data types to facilitate uniform search and analysis across diverse data sources, which is particularly beneficial in heterogeneous environments. Migrating to ECS involves translating data sources, resolving schema conflicts, and adjusting analysis content to accommodate ECS event formats. Beats 7 events are already ECS-compatible, but users with custom pipelines must map their event sources to ECS manually. To ease the transition, Elastic Stack 7 introduced field aliases, allowing new indices to recognize old field names, though these aliases have limitations and are meant to be temporary. The blog provides a detailed example of upgrading Filebeat from version 6.8 to 7.2, highlighting the steps necessary to reindex past data and modify incoming data to match ECS, while also addressing field conflicts and the usage of field aliases. The post emphasizes the benefits of ECS for scalability and reliability, encouraging users to update their environments and utilize provided resources and forums for guidance.