As CTV continues to evolve, the language around it can often feel as complex as the technology itself. But understanding the core terminology is not just about definitions, it’s about gaining a clearer view of how the ecosystem works and how its different parts connect.
A good CTV glossary is not about memorising jargon for its own sake. Half the challenge is understanding the market; the other half is decoding the language around it.
Because in CTV, language is not separate from strategy.
It is part of how the system reveals itself.
So here is the simplest useful way to think about a CTV glossary: not as a dictionary for buzzwords, but as a map of how the ecosystem works.
Key terms publishers should know
CTV (Connected TV)
A television connected to the internet, whether through a smart TV, streaming device, or gaming console.
OTT (Over-the-Top)
Video content delivered over the internet rather than through cable or satellite. OTT is the delivery method; CTV is often the device environment.
SSP (Supply-Side Platform)
A platform publishers use to sell inventory programmatically.
DSP (Demand-Side Platform)
A platform advertisers use to buy inventory programmatically.
Header Bidding
A way for multiple demand partners to bid on the same impression at the same time.
Waterfall
A sequential setup where demand partners are called one after another rather than competing all at once.
Mediation Layer
The control system that helps decide how different demand sources are managed and compared.
SSAI (Server-Side Ad Insertion)
A method of stitching ads into a stream on the server side, often used to improve playback smoothness.
CSAI (Client-Side Ad Insertion)
A method where ads are inserted by the app or device during playback.
SPO (Supply Path Optimization)
The process of identifying cleaner, more efficient routes between advertiser spend and publisher inventory.
Why this language matters
The easiest analogy is this: adtech terminology is like airport signage. Once you understand what the signs mean, moving through the system gets much easier.
For publishers, that matters because these are not just abstract terms. They describe the infrastructure that shapes revenue, demand access, playback experience, and buyer trust.