In what phase of the four application lifecycle milestones does this action belong?

Communicate Changes, Update Profiles and Communicate end of Changes are actions that belong to the Deploy phase of the four application lifecycle milestones. The Deploy phase involves moving changes from one environment to another and ensuring proper communication with stakeholders and end users. The Build phase involves creating solutions using declarative or programmatic tools based on requirements and design specifications. The Test phase involves verifying functionality, performance, security, and usability of solutions using various testing methods and tools. The Plan phase involves defining project scope, objectives, deliverables, resources, timeline, and risks. References: https://trailhead.salesforce.com/content/learn/modules/application-lifecycle-and-development-models/understand-the-application-lifecycle https://trailhead.salesforce.com/content/learn/modules/application-lifecycle-and-development-models/choose-a-development-model