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DevOps and site reliability both emphasize cross-team communication, shared responsibility, and automation – however, these mindsets are not identical.
DevOps is a broader philosophy applied to multiple technologies, while SRE has a tight focus: the latter is about a unit assigned to a specific project or tech stack. The SRE monitors the metrics valuable exclusively for a given case when DevOps watches all possible parameters. SRE is a DevOps implementation itself.