There are several ways to think about the differences between tags and collections.
- Tags are specific where collections are general. If you took photos at a birthday party, you will want to use tags to identify the people in the individual photos by name. You may also want to tag them as a birthday event, but you would probably use a collection to group all of the photos from one particular birthday party
- Tags are more permanent where collections can be temporary. Although you can use tags to flag several photos you want to use in a specific project, it's usually better to use a collection. The tags panel tends to get unwieldy very fast, so it's best to avoid tags when a collection will do. When your project is complete, you can delete the collection.
- Use tags to identify the content of your photos. Use collections as a container for holding similar groups of photos.
One other important difference between tags and collections is that photos in a collection can be arranged into a custom order. When you select a group of photos using tags, they are displayed according to date, import batch, or folder depending on what is selected from the arrangement menu. When you select photos from the Collections pane, they can be dragged and dropped into new positions. These positions will determine the order of the items when you create projects like slide shows or Web galleries. A small number in the top left corner of the thumbnail shows the item's position in the collection.
