When you buy a license to use Smedge, your license will last forever. Every license includes a one year support contract as well. This support contract is what expires. After your support has expired, you will still be able to run any version of Smedge released before the expiration date for as long as you want.
When the support contract expires, you will not be able to run any version of Smedge released after that date. You will also no longer be eligible for unlimited, free technical support.
You can renew your support contract at any time, including after it has already expired. The cost of a support contract is based on the number of licenses that you own. The new contract will allow you to run any version of Smedge released up to the new expiration date for ever.