Free VMware vSphere Hypervisor, Free Virtualization (ESXi)

In the above link it looks like the licence for the ESXi is free.

All we want to do is setup vmware esxi on a host we have in house to run a windows vm and a linux vm side by side.

Following the video on the site I am left with the impression the licence is free... but then following this link:  VMware vSphere 6.5 Documentation Library    It seems that it is not free and after a certain amount of time (60 days) the licence will expire and we wont be able to restart the virtual boxes.

Any help on what the free basic licence is would be absolutely great.

Cheers,

John