Transactions are itemized requests for Products or services, created from either the Administration Console or through the Online Store. They are classified by their "type":

Transaction Type Admin Console Only Description
Quote No An official estimate of the cost of one or more products or services.
Purchase Order No Used to track inventory purchases from Suppliers. Customers can create these Transactions indirectly by purchasing an item that is out of stock.
Online Order No A request for products or services placed through your online store via the checkout process.
Invoice Yes A bill for Products or services that have already been provided, or where advance payment is required.
Subscription Package Yes Periodically generates a Subscription Invoice until the end of it's term.
Inventory Adjustment Yes Used to track changes in inventory.
Shipping Statement Yes An itemized description of an order that can be included with their delivery.
Working Draft Yes A Transaction that is not fully prepared to be sent to a customer.

Once created, Transactions can be paid automatically through an online Payment Gateway, or by using "offline" methods such as cash or cheques. Transactions are then processed by your staff, marked as "completed" and archived.