Efi partition is related to windows installation or UEFI

Hello !
The EFI partition contents is related with a specific windows installations or with PC's UEFI ?
For example :
Let's have 2 PC :
- Different hardware
- GPT (Different / or Same ) Partition scheme
- Same version and editions of Windows 8.1

What can we say about EFI partition contents on these 2 PC ?
Thank you !

The EFI partition is the System Boot Files Partition (ie System partition)

GPT is a different partition format (allows more then 4 primary partitions, MBR only 4 primary partitions)

Very limited X86 support for GPT partitions and UEFI - system depending