The mechanism A pack is configuration, not a different product.
Pick one when you create the organisation, or apply it later from Settings. It writes
ordinary configuration rows into your org, all of which you can edit or delete afterwards.
Renames things to your words, on the web app
A pack writes a terminology map onto the org and the web app reads it: Deals, Leads, Accounts, Contacts and Invoices take your words in the navigation, and the Leads pages carry the new word throughout. Other page headings keep the stock label, and the phone app does not read the map at all, even though you can apply the pack from it. It is a rename, not a fork: the record underneath is the same one.
Adds the fields your trade needs
Between three and six custom field definitions per pack, on the entities where they belong. They show up on the web forms and the phone forms, filter in list views, and come back through the API like any other field.
Seeds tags and a product list
Four tags and six to eight products or services, priced and ready to put on an estimate. It is a starting point you can edit, not a locked catalogue.
Optionally fills it with sample data
Accounts, contacts, deals, tickets, tasks and leads, every row tagged so you can delete the lot in one action when you are done looking. Skip it and you get the configuration only.
One thing a pack builds that you cannot see yet
Every pack also defines a lead pipeline, a ticket pipeline and a task pipeline, with named
stages and work-in-progress limits. Those rows are created and the API serves them, and neither the web app nor the phone has a screen that draws them today. They are
listed here rather than counted as a feature, because a stage board you cannot open is not
one.