Scrum and Kanban are agile ways of organizing the work in a team.
Scrum is commonly used in software development, but not (yet) so much in other domains.
Kanban was invented by Toyota and is used in many different domains. Most domains that are implementing or using Lean are using Kanban as a way to organize work.
These are by far the most commonly use ways to organize the continuous development in agile organizations that has replaced the traditional waterfall model (that isn’t working, see Agile Foundation).
For more information on similarities and differences and how to choose see Scrum versus Kanban.