(This article refers to Collections store owners can create for their own products. For information about Collections anyone can create with products from any marketplace store, go here.)
Collections are just a fancy way of saying "product categories" and you can use them to divide up your products into sensible sections to make it easier for a customer to browse your store. For example, you might have a collection for women's clothes, one for men's clothes and one for shoes.
Add a Collection
You can manage your collections by going to the "Products" tab and then clicking "Manage Collections".
Choose a Featured Collection
If you use a theme which supports this, you can choose a featured collection. This will display this collection on your homepage instead of a view of all your collections. If your theme doesn't support this, the collection at the top of the list will be displayed on your home page (the default is "All Products"). You can choose a featured collection from the "Featured Collection" drop-down box by going to the Storefront tab and then Theme.
Rearrange the order of your Collections
You can rearrange your collections by clicking on the icon to the left of the collection and dragging it up or down. Whichever collection you place at the top will be the one shown when a customer first arrives at your store.
Edit the Collection
If you click on the collection you want to edit, you can select from a list of all your products. Click a product to add it to the collection, click it again to remove it.
You can also choose to upload a cover photo to each collection. This will be displayed on your store's homepage, if you use a theme which allows a collection display instead of a product display on the homepage.
Scroll further down below your list of products to see a list of just the products currently in the collection you are editing. Click on a product image to drag it around and rearrange the order the items are displayed within the collection.