Continuous Integration (CI) is the practice of merging code and automatically running a build process including tests whenever a developer commits code changes.
Infrastructure as Code (IaC) is the management of infrastructure (networks, virtual machines, load balancers, and connection topology) in a descriptive model, using the same versioning as DevOps team uses for source code.
Microservices describes the architectural pattern of composing a distributed application from separately deployable services that perform specific business functions and communicate over web interfaces.
DevOps culture stresses small, multidisciplinary teams, who work autonomously and take collective accountability for how actual users experience their software.