Platinum (or sponsored) open access
Allows immediate access to the content of a journal without subscription fees or article processing fees. All the costs of publishing the journal are covered by one or more sponsoring organizations.
Gold open access
Makes a journal article immediately freely available online. Authors pay Article Processing Charges (APCs).
Hybrid open access
Makes individual articles open access in a traditional subscription-based journal.
Delayed open access
Provides open access to the content of a journal upon the expiration of a specific embargo period.