Hi i am creating visualforce pages and apex classes triggers etc for last some time.i want to know what is app in salesforce and how to publish it on AppExchange? Any requirement for publishing app on app exchange i went through this tutorial link
they teach how to create an app in developer org by default there are 6 tabs Home,Chatter,File,Your Tab ,Reports,DashBoard.i basically want to know what app contains? apex class,visualforce page these components or only standard tabs and some customization tab what we see when we select an app in developer org
An app in Salesforce.com is nothing but a container which contains in it - a name, a logo, and an ordered set of tabs.
http://www.salesforce.com/us/developer/docs/fundamentals/Content/adg_simple_app_introduction.htm
All the metadata such as Objects, Visualforce Pages, Classes, etc are independent of an app. An app just helps to group things together visually. But internally the metadata has nothing to do with an app i.e. you can have the same tab, VF Page in multiple apps.
Publishing an app on AppExchange is a long procedure. Please follow the AppExchange Publishing Guide https://sites.secure.force.com/appexchange/resource/1237050882000/help/index_Left.htm for full details on how to publish your app on AppExchange.