A normal SaaS contract has two parties and that means one agreement. A agrees with B, which is the same as B agreeing with A.
But in a reseller scenario there are three parties involved. There’s the vendor, the reseller, and then there’s the reseller’s customer.
The reseller’s customer isn’t party to the reseller agreement but exists there implicitly because the reseller’s customer has to be taken care of and provided for in the reseller agreement.
Three parties mean 3 agreements, all living in one contract. A has to agree with B, B has to agree with C, and C has to agree with A.
It’s complicated.