With collections you can organize your products in your Products section and on your Sales Page.
Create a collection
In the Product section select Collections
Click on the + sign or + New collection
Add a name for the collection
Add an image which will appear on your Sales Page
Save
Add a product
Edit a product
In the Collection section choose a collection
Save the product
Add multiple products
Edit a collection
In the Product list section select Manage
Choose products from the list
Click Done and Save the collection
Products in Collections
Products ordered by collections on a Sales Page