When UPS says received by driver release it means the UPS driver released the package without a signature.
Sometimes I'll be outside when the UPS driver comes by to deliver a package and he'll hand me the package and then I don't need to sign for it.
Then it will set met customer man which means he met me and handed me the package.
The UPS driver can also just release the package and leave it on the porch when a signature is not required.
If a signature was required for the UPS package to be delivered the UPS driver would knock on your door, ring your doorbell etc and wait for someone to come out and sign for the package.
If you're not there to sign for the package then the UPS driver will take the package back and try the next day to deliver the package.
But most packages through UPS are left at your door or address without a signature even when you're not there.
Some UPS drivers may try to hide the package out of sight as well.
However the driver release by UPS just means the UPS driver released the package and left it at the address.