The Catalog provides three ways to manage the materials and labor you sell to your customers:
Products are Brand and Model specific items (aka equipment) that you sell and typically make up the bulk of your Catalog. Examples include speakers, cameras, and cable.
Allowances are a placeholder for materials that would otherwise be includes as a Product. Unlike their Product counterpart, they do not have a Brand or a Model and instead have only a name. Allowances are great for estimating and include a feature which allows the price of the Allowance to be calculated based on condition of an opportunity, that you define. This feature is unique to Allowances and is not available on Products. Examples include "Large television" or "Lighting Control System Allowance".
Services provide a way to budget for items that have no material cost but instead are only labor. This is intended for line item labor list "Basic remote programming", "Advanced remote programming", or "Site Survey". Services may contain any number of labor items which allows a single Service to address labor Opportunity wide like Project Management, Programming, and Installation.