Caml Query Client Object

I was wondering why the list query returns ALL of my list when the reason was that I have left out the <Query> tag! This is the working version...

                SP.List oList = context.Web.Lists.GetByTitle("Projects");
                CamlQuery camlQuery = new CamlQuery();
                camlQuery.ViewXml = "" + projectCode + "";
                ListItemCollection collListItem = oList.GetItems(camlQuery);
                context.Load(collListItem);
                context.ExecuteQuery();