At a high level, "devops" refers to a set of practices that emphasize the collaboration and communication of both software developers and information technology (IT) professionals while automating the process of software delivery and infrastructure changes. The word is literally "development" and "operations" combined together. Many more iterations exist of combining different elements like "security" into "devsecops".
See links below for resources about DevOps from the #devops channel on WWCDC slack.
Cloud computing is the delivery of computing services (servers, databases, networks, and more) over the internet.
Many clouds exist but the major cloud providers thath you will see most often in job descriptions are Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP).
A container is a lightweight, standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries and settings. Docker is a common, and Kubernetes and Openshift is used to manage a platform of containers.
Our ongoing Summer 2021 System Design Workshop notes can be found here.