Add-Ins. An add-in is a product which uses macros or other technology to enhance the native functionality of its Office host. In most cases, add-in products add one or more buttons to the toolbar, or they add new entries to the Office menu. These toolbar buttons and menu entries are used to access the add-in's features.
Hosted OLE Servers. Compared to an add-in, a hosted OLE server is a more sophisticated type of product, which uses OLE technology to extend its Office host's functionality via inplace editing or OLE automation. Like add-ins, OLE servers usually alter Office's toolbars or menus.
Hosted OLE servers must be clearly distinguished from standalone OLE servers. A hosted server is one which can only be used within its Office host. By contrast, a standalone server is either a file- or non-file-based standalone application which can operate as an OLE server. This distinction is important, because an OLE server which can operate as a standalone application will not be tested according to the hosted OLE server guidelines. Instead, it must comply with the requirements for other standalone products.
Content Products. A content product is one which contains information (but generally not executable instructions) that either controls the operation of its Office host or that can be displayed by Office for the user's benefit. Content products include templates, graphic objects, data files, and similar items. Office-related training tools also qualify as content products, as do World Wide Web sites and other Internet sites that distribute data in a format that can be displayed within Office. Note that some content products, such as sophisticated templates, contain such advanced user interface elements (e.g., buttons, dialog boxes) that the distinction between them and an add-in vanishes. In such cases, the product must pass the testing requirements that apply to add-in products. But for most content products, simpler testing requirements apply.