Shopify uses collections to group and display products within your online. A collection can include all of your products or only those that have been assigned to the collection.
You own an online store that sells clothing. Collections/all includes all the items you sell. Collections/shoes includes all the shoes you sell. Collections/sale includes all the items that have a reduced price.
The collection title is the default URL and page title seen by customers but can be changed later.
Collection type is used to determine which products will be displayed within the collection. A manual collection type allows you to add products to this collection one by one. An automated collection type uses the conditions you outline below to automatically assign products to the collection.
The products and sorting conditions of a collection can be changed at any time, however the collection type can only be specified during collection creation. Deleting a collection and replacing it is the only way to change the collection type.