Reference
This category borrowed most of its vocabulary from machine learning research and then used it in product copy without explaining any of it. The result is that the words which decide whether you enjoy a companion app — persona, memory, context window, filter — are the ones nobody defines. These entries define them.
Three places where the vocabulary is doing real work rather than decorating a feature list.
Two apps can both claim memory and mean entirely different mechanisms — one keeps the recent conversation in view, the other writes facts to storage and fetches them back. Knowing which is which turns a marketing claim into a checkable one.
When a character suddenly forgets a name, the cause is usually structural rather than personal. The vocabulary tells you whether you hit a window limit, a memory cap or a filter, and each of those has a different workaround.
A persona is a budget as well as a description. Understanding that the definition is resent with every reply explains why long, padded character sheets make a companion worse rather than richer.
Each entry is a definition first and an explanation second, so you can stop reading once you have what you came for.
A chat product built around an ongoing relationship with a consistent character, rather than around answering questions.
The maximum amount of text, counted in tokens, that a model can consider at once when producing its next reply.
Any mechanism that carries information from earlier in a relationship into a later reply, beyond what is currently visible in the conversation.
A one-directional bond in which a person feels closeness toward a figure who cannot reciprocate in the same way.
The written definition of a character — who they are, how they speak, what they know — that is supplied to the model on every reply.
A layer that inspects prompts or replies and blocks, rewrites or deflects content that falls outside a product's policy.
More entries are being written. Terms are added to this list when their page exists, never before — a reference work that links to missing pages is not a reference work.