New in SharePoint 2010 CAML Query, &Even though Microsoft encourages using LINQ in SharePoint 2010, they introduced some new CAML Query schema elements. They are IN INCLUDES NOT INCLUDES IN:This is something work as same as what we see in SQL Query.
Caml Query List
We can provide a collection of Items to filter. Previously in SharePoint 2007 we have to use OR operator to do this. But using OR for multiple times for multiple values will lead to lack in code clarity.