Can someone help me please. I want to know the difference between the recovery partition (400 MB) and the OEM partition (27 GB) on my laptop

Recovery Drive helps  to create the System image or recovery options which includes the software, utilities and Files saved on the system at the time of creating the image.One can use this at the time Windows 8 crash or repairing Windows 8.

Create a USB recovery drive

 

OEM recovery management or Recovery Partition is usually used to perform Factory restores.It saves the manufacturers supplying recovery disks.It consists of OEM copy of Windows and other software bundled by the manufacturer.