Recommended JFrog Artifactory Layout setup for Maven Projects
Within Artifactory there are three types of repositories:


Local: Local repositories are physical, locally-managed repositories
into which you can deploy artifacts 
Remote: A remote repository
serves as a caching proxy for a repository managed at a remote URL
Virtual: A virtual repository (or "repository group") aggregates
several repositories with the same package type under a common URL.


Local and remote repositories are true physical repositories (they exist either on your server on on a remote server somewhere else), while a virtual repository is actually an aggregation of them used to create controlled domains for search and resolution of artifacts.

If you need all of those types depends a bit on your use case. A real world use case for a remote repository would be Maven Central or jCenter where developers host their Maven packages. JFrog Artifactory can serve as a cache for those services so that not every call to resolve Maven dependencies has to go through the Internet. A real world use case for a virtual repository is that I have a remote repo (like the ones I already mentioned) and a few local repos too (like the ones you mentioned in your question). I want to make sure that my developers only need to configure one Maven repository as URL and my virtual repository allows me to do that. With a virtual repo, I can group together all sorts of other repositories and give one URL to developers so I can manage which dependencies are allowed as opposed to resolving them from the Internet every time.

Based on lessons learned we've included some default repositories into Artifactory that follow the flow of most developers that use Maven. Having said that, there is nothing stopping you from adopting your own workflow and not using the default repos.