In this article, How to download the SharePoint  library files in Document Library var file = clientContext.Web.GetFileByServerRelativeUrl(fileRef);                clientContext.Load(file);                clientContext.ExecuteQuery(); ...

Server Object Model? SharePoint server where the Server Object Model binaries Example inside Web Parts / Workflows. Client Object Model? client machines where the entire SharePoint binaries are not available. Example Windows Forms application in a client machin...

"Client" in the namespace.  For example, in the server object model you have: Microsoft.SharePoint.SPSite Microsoft.SharePoint.SPWeb Microsoft.SharePoint.SPList In the client object model you have: Microsoft.SharePoint.Client.Site Microsoft.SharePoint.Client.Web Microsoft.SharePoint.Client.List NameSpace: Microsoft.SharePoint.Client.dll Microsoft.SharePoint.Client.Runtime.dll Example...

"Client" in the namespace.  For example, in the server object model you have: Microsoft.SharePoint.SPSite Microsoft.SharePoint.SPWeb Microsoft.SharePoint.SPList In the client object model you have: Microsoft.SharePoint.Client.Site Microsoft.SharePoint.Client.Web Microsoft.SharePoint.Client.List NameSpace: Microsoft.SharePoint.Client.dll Microsoft.SharePoint.Client.Runtime.dll Example...

"Client" in the namespace.  For example, in the server object model you have: Microsoft.SharePoint.SPSite Microsoft.SharePoint.SPWeb Microsoft.SharePoint.SPList In the client object model you have: Microsoft.SharePoint.Client.Site Microsoft.SharePoint.Client.Web Microsoft.SharePoint.Client.List NameSpace: Microsoft.SharePoint.Client.dll Microsoft.SharePoint.Client.Runtime.dll Example...