Supplier is SONM user, that is the resourse owner. Suppliers can earn SONM tokens by selling computing power peer-to-peer to Consumers and perform their calculations.
Every Supplier should have his own Ethereum master account, that is his unique identifier. The master account receives all incomes and hold Supplier's profile and rating, enables Worker monitoring and setting up.
For Supplier main algorithm of using SONM is:
Full description about getting started as a Supplier is here.