DevOps is a set of practices that combines software development and IT operations. It aims to shorten the systems development life cycle and provide continuous delivery with high software quality. DevOps is complementary with Agile software development; several DevOps aspects came from Agile methodology.
Site reliability engineering (SRE) is a software engineering approach to IT operations. SRE teams use software as a tool to manage systems, solve problems, and automate operations tasks.