Reseller
Buys at a transfer price and sells at its own price. Owns the customer contract and usually first-line support. Earns the difference between the two prices.
Value-added reseller
A reseller that adds implementation, configuration, training, or complementary products. In practice most value-added resellers earn more from their services than from product margin, which shapes what they will sell and how hard.
Distributor
Sits between vendor and reseller. Aggregates many products, carries credit risk, and handles logistics and billing for a network of smaller resellers. Gives the vendor one commercial relationship instead of dozens.
Referral partner
Introduces prospects and takes a fee. The vendor runs the sale, holds the contract, and owns the customer. Simple to set up, low commitment on both sides, and correspondingly limited in what it produces.
Systems integrator or consultancy
Embeds your product inside a larger project it is already delivering. Frequently influences far more revenue than it sources, which is precisely why the sourced and influenced distinction matters.
Managed service provider
Wraps the product into a service it sells and operates. The end customer is theirs in every practical sense, including renewal risk.