A supply-side platform (SSP) is an advertising technology platform used by publishers to manage, sell, and optimize their advertising inventory. SSPs are also known as sell-side platforms and are a key part of the real-time bidding (RTB) process within programmatic advertising. They allow publishers to connect their inventory to multiple ad exchanges and demand-side platforms (DSPs) simultaneously, enabling them to optimize yield and maximize revenue. SSPs provide the technology and resources that enable publishers to aggregate, consolidate, and manage their demand sources. Publishers set brand safety guidelines, categories, and pricing, and the SSP holds an auction that takes all of these factors into account, with the highest bidder winning the auction. SSPs also provide publishers with insights on the value of their inventory for different advertisers, allowing them to optimize for maximum profits. Some of the main features and components of an SSP include real-time bidding transactions, frequency capping, and relevancy. SSPs offer a number of benefits to publishers, including automated selling of inventory, better brand safety, and the ability to sell all of their inventory to advertisers.