Collections, Sets, & Galleries
Images in your photostream can be organized into Sets, which are like a single album of photos. This album may contain photos from a single event, or a certain group of people, or on a particular subject. You can create as many sets as you'd like, which act like separate folders for the photos you upload.
If you want to combine those Sets with other photo albums, from other events, different people or subjects, you can organize them into Collections, which combine various Sets into a greater volume of photos. This way, if you have a series of photos from different events you want to organize, each event may have it's own Set, but each Set appears in the appropriate Collection.
An additional feature of collections are Mosaics. Mosaics are a preview of the images in your Collection, which appear on the cover of that collection. You can arrange and edit a mosaic using the tools in Flickr.
Galleries are a way to reference another user's photos and link them from your photostream. If there are other users on Flickr with photos you want to direct your visitors to, such as other University Units who are hosting pictures related to your own purposes, creating a Gallery will point visitors in that direction.
Tags and Geotags
Tags are a useful way to organize and order your photos along with sets. When you tag a photo, you apply a keyword to the image which can be referenced in a search. So a photo of a University Unit officer or administrator may be tagged as "officer." Other photos tagged this way will appear alongside the original in a search for that tag.
Geotags are a way to link locations with your images. Photos taken at landmarks, local establishments, and so on, can be tagged on a map, which will help connect community locales with your photo albums. They can also direct users to an administrator's office, offices of the University Unit, sites for recent events, and so forth.
Notes provide a way to highlight content in your photos with additional information. For instance, if you want to identify people in a photo, tagging them in the photo will allow users to scroll over the tagged area and see what text you've entered there. It also helps users who are searching through your photos to find what they are looking for; when a user runs a search, Flickr will go through the title and the description of a photo as well as any notes you've added to the photo.