A break glass account is a special, privileged emergency access key (or an actual user account, or service account) designed for rare, critical scenarios. You use it when normal sign-in systems fail or when immediate administrative action is required.
The term itself refers to breaking the protective glass to access emergency equipment; these accounts remain dormant under strict controls until an urgent situation demands their use.
Unlike your standard administrative accounts, break glass accounts are designed to bypass typical access control mechanisms to restore system functionality during outages, security incidents, or infrastructure failures.