AI Companion Glossary

AI companion

An app built around an ongoing, personal relationship with a chatbot — a girlfriend, boyfriend, friend, or character you talk to over time. Unlike a general assistant, a companion is designed to remember you, hold a persona, and feel like a continuous relationship rather than one-off Q&A.

AI girlfriend / AI boyfriend

A companion app configured as a romantic partner. You design the character's looks and personality, then chat by text (and often voice or images). The label is marketing as much as anything — under the hood it's the same large-language-model technology as any other companion app. Best AI girlfriend apps →

Large language model (LLM)

The AI that actually writes a companion's replies. An LLM is a model trained on huge amounts of text to predict natural-sounding language. Every companion app is a product wrapped around one — either a major model (like GPT- or Llama-family models) or the company's own fine-tuned version.

Context window

How much of your recent conversation the model can 'see' at once, measured in tokens. When a chat runs past the context window, the earliest messages fall out of view — which is why a companion can suddenly forget something you said much earlier unless it has a separate memory system.

Memory (long-term memory)

A feature that stores facts about you and your relationship outside the live context window, so the companion recalls them days or weeks later. Strong memory is the single thing that most separates a convincing long-term companion from a generic chatbot that resets every session.

Token

A chunk of text (roughly ¾ of a word) that language models read and write in. 'Token' is also confusingly used by some apps as the name of their paid in-app currency — see Credits. When we talk about the model, a token is a unit of text; when an app sells you tokens, it means credits.

Credits / tokens (in-app currency)

A virtual currency some apps charge on top of (or instead of) a subscription, usually to meter image and video generation. Credit systems are where 'cheap' plans get expensive fast, so we always decode what a credit actually buys and flag apps where they deplete quickly. What AI companions really cost →

Freemium

A free-to-start model where core use is free but the best features sit behind a subscription. Almost every companion app is freemium; the honest question is how much you can actually do for free before a paywall — which is exactly what our free-apps ranking measures. Best free AI girlfriend apps →

Roleplay (RP)

Collaborative, story-driven chat where you and the AI play characters in a scenario. Roleplay-first apps emphasize narrative, character cards, and scene-setting over a single 'partner', and range from polished and filtered to fully uncensored. Best AI roleplay apps →

Character card

A reusable definition of a character — name, personality, backstory, speaking style, and sometimes an avatar — that you load into a chat. Community libraries of character cards are the backbone of roleplay platforms like Character.AI and Janitor AI.

Persona

The personality and behavior settings that shape how a companion talks — caring, confident, playful, and so on. Adjusting the persona changes the tone and content of conversations, and is the main lever most apps give you beyond appearance.

NSFW

'Not safe for work' — adult or explicit content. In companion apps it usually refers to sexual roleplay and uncensored images. All NSFW use is intended for adults (18+); availability and limits vary widely by app and region. Best NSFW AI chatbots →

SFW

'Safe for work' — non-explicit content. SFW-focused apps (like Replika or Character.AI) lean toward friendship, emotional support, and PG-rated roleplay, with stricter content filters.

Content filter

Automated moderation that blocks or redirects certain topics. Filters are why a chat may suddenly refuse or deflect. 'Uncensored' apps loosen these; mainstream apps keep them strict for safety and platform/payment-processor compliance.

Uncensored / unfiltered

Marketing shorthand for apps with looser content filters that allow adult or taboo roleplay other platforms block. 'Uncensored' is rarely absolute — every app still enforces some hard limits (notably anything illegal), regardless of how it's advertised.

Jailbreak

A prompt trick used to get a model to ignore its own restrictions. Jailbreaks are unreliable, against most apps' terms, and unnecessary on platforms designed to be uncensored in the first place.

In-character image generation

Generating pictures of your specific companion, on request, that stay visually consistent with the character you designed — as opposed to a generic image generator. Quality and consistency vary a lot, and credits usually meter how many you can make. Best companions with image generation →

Voice / text-to-speech (TTS)

Spoken replies and, on some apps, real-time voice calls. Voice adds warmth and presence text can't carry; the things that separate good from robotic are naturalness and latency (how quickly it responds). Best companions with voice →

Proactive messaging

When a companion messages you first — a 'good morning', a check-in, a nudge to come back. It boosts the feeling of a living relationship, but it's also an engagement (and retention) mechanic worth being aware of.

Fine-tuning

Further training a base model on specialized data to change its style or capabilities — for example, to make it better at romantic roleplay or to relax certain refusals. Many companion apps run a fine-tuned model rather than a stock one.

Waifu

Internet slang (from anime fandom) for a beloved female character — often used for anime-style AI companions. 'Waifu apps' emphasize anime/manga art styles and characters. Best anime AI companions →

Billing descriptor

The text that shows up on your bank or card statement for a charge. Privacy-conscious companion apps use a discreet, non-obvious descriptor; we note each app's descriptor so there are no surprises.

Missing a term? Let us know and we'll add it.