Humio organizes data into Repositories (or Repos). Each repository has its own set of users, dashboards, saved queries, parsers, etc.
A repository is a container for data with associated storage. Often you will have one physical repository per project or system. But use-cases vary based on your data volume, user permissions and many other factors.
On a repository you can control retention and create parsers to parse incoming data.
When sending data to humio it will end up in a repository.
The repository has a close cousin called Views. Views are similarly to the views you may know from SQL databases.
Views lets you search across multiple repositories. They also have user management and search filters, making it possible to define which users can see what data. This is how fine grained access controls is implemented in Humio
You can search directly in a repository, or search through a view. Using a view can give added benefits, e.g.:
You can read more about views in their doc section.
All accounts have a special private repository called the sandbox. Unlike other repositories you cannot add additional users or change retention. You can use the sandbox for testing things out or as the your main repo if your needs are simple.