Thingiverse is an online community where users upload and share a wide array of files that can be 3D printed. Files are free to download under a Creative Commons license.
Thingiverse allows anyone to download 3D models, no account or sign-in required. You can browse through popular items, various categories, or search using specific keywords.
Once you find a model you would like to submit for 3D drop-off, there is no need to download the files -- unless you are previewing them in Cura to get an idea of how long they will take. Simply copy the URL and fill out the form in the Submit Your Drop-off section.
Thingiverse uses Creative Commons licenses to allow other users to download, modify, and distribute 3D models on the site. However, there are different types of these licenses that allow for different usage. Some, for instance, may restrict commercial use of the 3D model.
Use the links below to learn more about Creative Commons copyright.