The encoding ladder is the set of quality variants — each a combination of resolution and bitrate — that a single title is encoded into so the player can switch between them as network conditions change. A typical ladder might run from a 240p/300 kbps rung for a weak mobile connection up to 1080p or 4K at several megabits for a fast wired link, with several rungs in between.
The ladder is the contract between encoding and playback: the encoder produces the rungs, the manifest advertises them, and adaptive bitrate (ABR) logic in the player climbs up and down them to keep playback smooth. Designing it is a balancing act — too few rungs and the steps between qualities are jarring; too many and you waste encoding compute and storage. Each rung also multiplies delivery and storage cost.
A fixed ladder applies the same rungs to every title, while per-title and context-aware encoding tune the rungs to the specific content, capturing the same quality at lower bitrate.
