SharePoint hosted vs Cloud hosted apps

Difference between SharePoint hosted apps and cloud hosted apps?

An app for SharePoint can have both SharePoint-hosted and cloud-hosted components. The app does not (actually cannot) contain custom code that executes on the SharePoint servers, administrators are assured of its safety.

Cloud hosted:  

1. This type of hosting is used when app has at least one remote component. It may also include SharePoint hosted components. There are two types in Cloud hosted apps.
2. The external components [also called Remote components] are persisted in databases, servers, or cloud-based services that are external to the SharePoint farm.
3. Cloud-Hosted Apps are also referred to as server-side apps.
4. Cloud-Hosted SharePoint 2013 Apps include components hosted outside your SharePoint farm. Such components can be hosted on IIS servers, Apache servers, or cloud services such as Windows Azure.
5. When it is required exactly is if we require server-side components in apps. In such situations, you must write a Cloud-Hosted App. Also known as server-side apps.

Provider-hosted:

1. Provider-hosted apps for SharePoint include components that are deployed and hosted outside of the SharePoint farm.
2. Apps for which the non-SharePoint components are deployed. Provider hosted apps can run on the cloud [SharePoint online] or on the own server [on-premises] depends on where you hosted them.
3. Benefit: The provider-hosted app for SharePoint can be hosted on Windows Azure or any remote web platform, including non-Microsoft platforms.

Autohosted:

1. Autohosted apps for SharePoint are hosted on Windows Azure Web Sites.
2. Benefit: When you deploy an autohosted app for SharePoint, all Windows Azure and SQL Azure components are provisioned for you when the app for SharePoint is installed. The Windows Azure Web Sites infrastructure handles load balancing, multi-tenancy, and other important maintenance tasks for you.
3. This will be used when apps that include Windows Azure web site, may has SQL Azure database. These apps will run in the cloud.

SharePoint hosted:  

1. SharePoint-hosted apps for SharePoint are installed on a SharePoint 2013 website, called the host web, and that have their resources hosted on an isolated sub site of a host web, called the app web.
2. Apps that include only SharePoint components and logic that runs on client. SharePoint hosted apps are hosted in SharePoint itself.
3. We can use any language such as HTML, JavaScript, PHP, .Net etc. to build the apps for SharePoint.
4. SharePoint components are persisted within the SharePoint content databases such as list templates, workflows, modules, site pages, webparts and custom content types.
5. SharePoint Server-Side Code in Apps is not allowed.
6. SharePoint-hosted apps also benefit themselves from existing resources and technologies in SharePoint such as the Ribbon, web part infrastructure and client-side rendering.
7. SharePoint hosted Apps are always scoped at web level and cannot exchange information with other apps. AppWeb has a unique address which in turn uniquely identifies an App.

Difference between SharePoint components and external components?

1. SharePoint components are persisted within the SharePoint databases such as list templates, workflows, modules, site pages, webparts and custom content types.
2. The external components [also called Remote components] are persisted in databases, servers, or cloud-based services that are external to the SharePoint farm.