Q. How can I fetch a specific object from Active Directory?

A. With the various AD cmdlets you can search for objects using the filter parameter however if you need to fetch a specific object you should use the identity parameter and pass the distinguished name of the object. For example:

Get-ADOrganizationalUnit -Identity "OU=Devices,OU=NA,DC=SAVILLTECH,DC=NET"

Get-ADUser -Identity "CN=John Savill,OU=Admins,DC=savilltech,dc=net"