What is License Entitlement?

I have set a Keil MDK (FlexNet) license which I use, and on the receipt for the license there is a maintenance date and an entitlement date. The entitlement date is set to 2124, but does this mean I will not have to purchase a new license as long as I don't need maintenance? We only have one product that uses this license, so I don't think we'll need maintenance updates since what we have works as-is so far.