Final answer:
To check if content in Wikipedia Commons is under a Creative Commons license, view the file description page for the license info. Content may show a CC license, like CC BY-NC-SA 4.0, indicating how it can be used and shared.
Step-by-step explanation:
To find out if content in Wikipedia Commons is available under a Creative Commons license, you should look at the file description page where the licensing information is displayed. Each media file uploaded to Commons is required to have a clear statement of its license. For example, if content is marked as CC BY-NC-SA 4.0, it means that the work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 license. This license allows you to share and adapt the work for any non-commercial purpose, as long as you give appropriate credit, provide a link to the license, and indicate if changes were made. If you redistribute the work or the modified version of it, you must do so under the same license. Wikimedia Commons provides a variety of licensing options, including Creative Commons licenses, public domain dedications, and other free licenses.