Writing CAML Queries For Retrieving List Items from a SharePoint List

PostRankWidget: "Introduction
The Collaborative Application Markup Language (better known as CAML) is an XML-based query language that helps you querying, building and customizing Web sites based on Windows SharePoint Services. The XML elements define various aspects of a WSS site.
In this first series of articles I will explain in detail how to build and execute CAML queries to retrieve list items from a SharePoint list. List items can be retrieved in several different ways: using the SharePoint object model, using the SharePoint Lists web service or even by using Powershell. Use the SharePoint object model when your code runs on the server (like f.e. when you’re developing a web part or an application page). Use the SharePoint Web Services when your code doesn’t run on the server where SharePointis installed, for example when you develop office clients or windows applications. Powershell, at the other side, can be used by administrators when they quickly need to retrieve some information. In any way the CAML query is the same."