You can think of a repository as long-term secure storage for the datasets you make available. You might keep your working data in Box, local storage, or OneDrive but the final datasets you want to make public should be placed in a specialized data repository. Repositories make your data easier to find and access as well as provide long-term safety and support.
Before selecting a repository, double check your grant proposal requirements to ensure there are not additional stipulations on where you can deposit your data. For example, NASA requires that all research data be submitted to their STI Repository.
The repository you use should align with your data needs. It is good to consider the following elements when choosing a repository:
Note that it may make sense to submit your data to more than one repository, just check your funding agency's policies first.
If your grant application does not specify repositories, Re3data and FAIRsharing are great places to start searching for an appropriate repository. Additionally check your field's organizations for sponsored repositories.