Shopify collections are groupings of products you can set up, to make it easier for your customers to browse all products within a certain category. For example, a fashion merchant might set up a collection of men’s shirts. A home décor Shopify store could set up a collection of lamps.
You can also set up seasonal collections, like summer essentials, or collections of products that are all on sale. You can show your customers a list of all your collections, so they can easily find the selection of products they’re interested in and start browsing.
Another option is to set up an all products collection on Shopify. When you create a Shopify all products collection, every product in your catalog is included in the collection, allowing your customers to browse your entire inventory if this is something they want (and you want to allow). Listing all products in a collection like this is a good idea if you have a relatively small product catalog.