In SharePoint 2013 there is a new custom component called
the apps for SharePoint. This is the recommended way for developers and third
parties to create new functionality and user interface components. SharePoint
2013 Apps infrastructure also benefits SharePoint administrators by making it
easier to manage the life cycle of custom applications. The following features
are included are included with the Apps
SharePoint Marketplace. This global marketplace for apps for SharePoint is a single
repository of custom components, available to all SharePoint customers.
Administrators can enable users to purchase apps, on behalf of the company from
the marketplace, or restrict that right to a small number of budget holders.
Once purchased, an app becomes available to all users in the SharePoint farm.
Corporate App Catalog. This catalog is a private repository of apps within the
SharePoint farm and controlled by farm administrators. Users can choose to
install these apps in any SharePoint site in the organization.
Apps for SharePoint are contained entirely within a sub-site of the SharePoint
site in which it is used. Therefore, when a user or administrator removes the
app, the sub-site is removed cleanly and no objects are retained in the parent
site or elsewhere. This clean removal aids app management.
Apps in Multi-Tenant Farms. In a multi-tenant SharePoint farm, there is a one Corporate
App Catalog for each tenant organization. This ensures that both tenants must
pay for their app usage and that removals do not impact other tenants.