In the CSAPI, manager objects are in charge of managing one or more types of entities collections. All entity types are managed by a particular manager type. For example, ISite manages IPage.

All manager objects are retrieved from an IUserSession instance and should only live within the scope of the current session. A manager object doesn't function if the session it belongs to is closed or disposed.

CMS_Common common = CMS_Common.GetCommonInstance(context.Request.RequestContext);
IContentStore contentStore = common.ContentStore;
IReadonlyUser currentUser = store.GetStartingUser(@"yourfirm\youruserid");

using (IUserSession session = store.OpenWriteSession(currentUser))
{
       IUserManager userManager = session.UserManager;
       IUser author1 = userManager.User("ingeniux\author1");
       ...
}

Note that manager objects are created only once per session. It is always the same manager instance being referred returning from a particular manager property on the IUserSession object.

The following list includes all manager objects:

ISite

ISettings

IGlobalVariablesCollection

ISchemaManager

IPageCreationRulesManager

IPublishingManager

IMobileDeviceManager

IUserManager

IWorkflowManager

ISiteMap

IGlobalExports

ITaxonomyManager

IReferencesManager

IAssetSecurityManager

ILingualMappingManager

ISecurityDescriptorsManager

ILocalesManager

ISiteContentLocalizationProvider

Reference