SharePoint 2013 is a strong development platform for building solutions and apps addressing different requirements and needs.
In SharePoint 2013 there is a new custom component called the apps for SharePoint.
Features of Microsoft SharePoint 2013 Apps :
The following features are included:
1. 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.
2. 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.
3. Removing Apps : Apps for SharePoint is 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.
4. 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.
There are three high-level types of SharePoint apps:
SharePoint-Hosted:These types of apps are manifested within SharePoint generally without external dependencies. Any custom business logic implemented with custom code must run within the context of the browser client. Some examples of these types of Apps could be an expense calculator or holiday request. Each of these Apps may implement its own business logic using JavaScript, but they can also access and leverage SharePoint lists and libraries.
Provider-Hosted:
These types of apps may have a SharePoint component but the bulk of the business logic is manifested in some other infrastructure, such as an external Web server or in the cloud. These types of apps are a good option when integrating an existing event registration or help desk ticketing solutions within a SharePoint site.
Auto-Hosted:
These types of apps are similar to the Provider-Hosted Apps in that they have the bulk of their business logic and/or data storage manifested externally. What’s different with an Azure Auto-Hosted app is that the app package contains the website & database in the package.
When the app is installed in a site, SharePoint handles the automatic provisioning of the database (as a SQL Azure database) and website (as an Azure hosted website) using an account that has been setup by the SharePoint farm/tenant administrator.