Final answer:
A tag is a key-value pair used in cloud environments to attach customized labels to resources for better management, including categorization and cost tracking.
Step-by-step explanation:
A tag is a key-value pair that attaches a customized label to cloud resources. It's an important part of cloud resource management that allows users to categorize their cloud services in various ways, such as by purpose, owner, or environment.
Tags can facilitate easier sorting, filtering, and aggregating of cloud resources, which in turn supports better organization, resource tracking, and cost allocation. For example, tagging resources related to a specific project enables quick access to all associated services and simplifies the monitoring of project-related costs.