Back to Basics - 2 SharePoint 2010 Server Object Model

Server Object Model in SharePoint is a large and critical classes helps developers to manage

1. Physical object hierarchy : classes represent physical components like servers and farms.
2. Content  hierarchy  : classes that represents publishable items of data and the nested containers of data.
3. Services hierarchy : includes classes that represent web services, Windows services, other types of services, instances of services, and CFSIs of services. 

Main classes in Physical object hierarchy are

• SPFarm : represents a sharepoint farm and its config DB.* 
• SPServer : represenets a physical server in the farm.*
• SPService : represents a farm-wide service. *
• SPSolution : represents a solution on a farm.

Main classes in Content  hierarchy  are

• SPWebApplication : represents a sharepoint web app. *
• SPContentDatabase : represents a content database that contains all the data and the customized page files that constitute the site collections that belong to the database. *
• SPWeb : represents a single website. 
• SPSite : represents a collection of websites within a SharePoint web application that are grouped together for mainly administrative reasons (Among the SharePoint elements that can be scoped to the site collection level are master pages, Web Parts, themes, lists, content types, and Features. A site collection can also be a unit of backup and restoration. It is also the level at which groups of users are created and assigned default permissions. Site collections are the largest possible scope for a search in SharePoint Foundation, although broader search scopes are possible in SharePoint Server 2010. The content of a site collection is always included within a single content database.)
• SPList : represents a sharepoint list and it  has members for programmatically adding, deleting, and retrieving list items, and also for managing metadata about the list such, as its content types and fields. 
• SPListItem : represents individual items of a list and it has members for managing the item's fields, the values of its fields, its content type, and any associated workflows. 
• SPFolder : represents Folders of a List which give a hierarchical structure. 
• SPField : represents field (column) on a list item.

Main Calsses in Services hierarchy are 

• Child class of SPService : represent sharepoint service which provides members that get info about the jobs the service is performing.
• Child class of SPServiceApplication : represents CFSI of a service  *
• Child class of SPServiceInstance : represents each instance of a service. A given CFSI can run on multiple servers, in which case each server has its own actual instance (a running process) of the CFSI. If the service has no CFSIs, it still has instances on each server on which it runs, but there can be no more than one instance of such a service on a given server. 
• SPServiceProxy & SPServiceApplicationProxy  : Applications that consume services that conform to the framework are represented by proxies. The consumer proxy for a service is represented by an SPServiceProxy object and the proxy for the CFSI is represented by an SPServiceApplicationProxy object.*

* inherits from SPPersistedObject, which means that the object that instantiates the class persists in the configuration database