Sharepoint 2010 of 14 hive directory structure introduction

Microsoft has replaced the "12 hive" structure that we had in
SharePoint 2007 with "14 Hive" structure in 2010.

Some of the folders in
14 hive are :

Program Files\Common files\Microsoft Shared\Web Server
Extensions\14 -
This directory is the
installation directory for core SharePoint Server files.

Program
Files\Common files\Microsoft Shared\Web Server
Extensions\14\ADMISAPI -
This
directory contains the soap services for Central Administration. If this
directory is altered, remote site creation and other methods exposed in the
service will not function correctly.

Program Files\Common
files\Microsoft Shared\Web Server
Extensions\14\CONFIG -
This directory
contains files used to extend IIS Web sites with SharePoint Server. If this
directory or its contents are altered, Web application provisioning will not
function correctly.

Program Files\Common files\Microsoft Shared\Web Server
Extensions\14\LOGS -
This directory
contains setup and run-time tracing logs.

Other newly added folders are
:

Program Files\Common files\Microsoft Shared\Web Server
Extensions\Policy -


Program
Files\Common files\Microsoft Shared\Web Server
Extensions\UserCode -
This directory
contains files used to support your sandboxed solutions.

Program
Files\Common files\Microsoft Shared\Web Server
Extensions\WebClients -
This directory
contains files related to the new Client Object Model.

Program
Files\Common files\Microsoft Shared\Web Server
Extensions\WebServices -
This
directory contains new wcf or .svc related files.

Note : You should
rewrite and recompile any code that refers to files and resources in "12" Hive
structure.For example, if you have redeployed all of your files into the "14"
folder and emptied your "12" folder, any references to files under the "12"
folder will not work.

See more details @ 14 hive and other directories of SharePoint 2010