Architecture
Architecture-related concepts, model families, and component patterns. Each entry links to a canonical docs page when published.
- Alignment
The post-pretraining goal of shaping a broadly capable base model toward helpful, safer, preference-following behavior before or during deployment.
- Alignment
Post-training steps that steer a model toward helpful, honest, and policy-compliant behavior—often via preference data, reward models, or safety filters.
- Architecture
The blueprint that defines how a model's layers, modules, and data flow connect during inference.
- Attention with linear biases (ALiBi)
A positional idea that subtracts larger attention penalties for farther token pairs instead of storing explicit position embeddings.
- Autoregressive Generation
A generation paradigm that produces outputs one discrete step at a time, each step conditioned on everything generated so far.
- Classifier-Free Guidance
A diffusion inference technique that steers denoising by comparing prompt-conditioned and prompt-free predictions, then blending them with a guidance scale.
- Component
A finer-grained part inside a module, such as an attention head or projection layer.
- Computational Graph
A record of which operations produced each tensor so automatic differentiation can run backward.
- Conditioning
Extra inputs—text prompts, class labels, images, or guidance weights—that steer a generative model without retraining the full parameter stack each time.
- Context extension
Common techniques that stretch usable context beyond a model's original training window without rebuilding the entire architecture from scratch.
- Context window
The maximum number of tokens a model can attend over in one forward pass, distinct from training sequence length and how many tokens it may emit in a session.
- Decode
The repeated next-token stage that reuses the KV cache and turns inter-token latency into the main reader experience after prefill finishes.
- Decoder
A network stack that turns internal representations into outputs—tokens, pixels, or structured predictions—often one step at a time with attention to prior context.
- Denoising Generation
A generation paradigm that starts from noisy latents and iteratively removes noise—or adds structure—until a clean sample emerges.
- Diffusion Model
A generative model family that learns to reverse a noise corruption process through many iterative denoising steps.
- Discriminative Model
A model trained to score, rank, or classify inputs into labels or preferences rather than synthesize new content.
- Embedding
A learned vector that turns discrete tokens, image patches, or other inputs into numbers a model can process.
- Embedding
A dense vector that represents a token or other discrete item so the model can run continuous math on it.
- Emergent Behavior
Qualitative capability jumps that appear only past certain model scale or training thresholds—distinct from smooth metric improvements tracked by scaling laws.
- Encoder
A network stack that maps raw or patched inputs into internal representations—tokens, latents, or context vectors—for downstream decoders or heads.
- Encoder-Decoder
An architecture that compresses input into representations with an encoder, then generates outputs with a decoder—often via cross-attention between the two stacks.
- FLOPs
Floating-point operations counted to estimate how much arithmetic work a model needs during inference, before teams compare serving cost, throughput plans, or hardware capability.
- Flow matching
A generative training objective that teaches a model how samples should move from a simple or noisy starting state toward real data.
- Foundation Model
A large pretrained model intended as a shared starting point for many downstream tasks via fine-tuning or prompting.
- Generalization
How well a model performs on data it was not explicitly trained to memorize—validation sets, new domains, and live traffic are the practical tests.
- Generative Model
A model trained to produce new outputs such as text, images, or audio rather than only assign labels to fixed categories.
- Inter-Token Latency
The serving latency metric that measures the delay between streamed output tokens after generation has started.
- Key-value cache
Saved key and value tensors from earlier tokens that let later generation steps reuse attention state instead of recomputing the full prefix.
- KV cache
The saved key and value tensors a decoder keeps from earlier tokens so later tokens can reuse attention state instead of recomputing the full prefix.
- Latent
A compressed internal code that summarizes input structure for reconstruction, generation, or downstream tasks.
- Latent Space
A learned compressed representation space where models store internal codes instead of raw pixels or token ids, then decode or denoise back to visible outputs.
- Memory bandwidth
How quickly weights, activations, and KV cache bytes can move between memory and compute during model serving, and why that movement can cap useful throughput.
- Mixture of Experts
A broad sparse-routing architecture pattern that activates only a few expert sub-networks per token instead of one dense path for every token.
- Modality
The kind of input or output data a model is built to handle, such as text, images, audio, or video.
- Model
A trained machine learning system that maps inputs to outputs using learned parameters.
- Model Capacity
How much function a model can represent—driven by parameter count, width, depth, and training data—before optimization and regularization constrain what it actually learns.
- Module
A reusable building block inside a model architecture, such as attention or a feed-forward network.
- Multimodal Model
A model family that accepts or produces more than one data modality, such as text paired with images or audio.
- Normalization
Keeping activations on a predictable scale so deep model stacks stay trainable and their sublayers receive stable inputs.
- Normalization
Layers that rescale hidden vectors inside each transformer block so activations stay stable as depth and batch composition change.
- On-policy training
Learning from examples or trajectories produced by the model or agent policy that is currently being updated.
- Overfitting
When a model fits training noise so closely that held-out or production data perform worse—the classic gap between memorization and useful generalization.
- Page Spec Workflow Sample
A small generated concept page that demonstrates the page-spec bundle workflow end to end.
- Patch
A fixed-size chunk of input data—pixels, spectrogram frames, or grouped tokens—that an encoder turns into a representation vector.
- Perplexity
A standard language-model evaluation metric: exponentiated average cross-entropy over tokens, lower is better when comparing models on the same corpus.
- Positional encodings
How transformers inject order into otherwise permutation-invariant attention through absolute, relative, and rotary position schemes.
- Prefill
The prompt-processing stage that reads the full input once, builds the first attention state, and sets up generation before any reply token appears.
- Prefill/decode split
The serving setup that separates prompt processing from token-by-token generation because the two stages stress hardware, memory, and latency in different ways.
- Regularization
Training-time and model-design choices that discourage brittle memorization so a model is more likely to perform well on new examples.
- Representation
An internal encoding of input data that downstream layers or tasks use instead of raw features.
- Residual connection
Skip paths that add each sublayer's output back onto the running hidden stream so deep transformer stacks stay trainable.
- Roofline model
A throughput-ceiling chart that shows when memory movement or arithmetic compute limits attainable performance, using arithmetic intensity to explain which bound is active.
- Scaling Law
Empirical power-law relationships between model scale, compute, data, and downstream loss or capability—used to forecast training budgets and benchmark trends.
- Self-attention
How a token reads other tokens from the same sequence so a transformer can mix context before producing the next representation.
- Skip connection
A broader shortcut path that carries information around one or more layers, including the residual adds used inside transformers.
- Special Tokens
Reserved tokenizer markers such as beginning-of-sequence, end-of-sequence, padding, and separators that carry structural meaning instead of ordinary text meaning.
- Synthetic Data
Training material produced or transformed by one model to teach another, distinct from raw web corpora collected for pretraining or demonstrations written directly by people.
- Text-to-image conditioning
Extra prompt-derived vectors that steer an image generator while the denoiser removes noise step by step.
- Throughput Vs Latency
The serving tradeoff between aggregate completed work over time and the wait experienced by an individual request under concurrency.
- Time To First Token
The serving latency metric that measures how long a reader waits from request start until the first generated token appears.
- Token
The smallest unit of text a language model reads and predicts—usually a word piece, not always a whole word. Each token ID maps to a dense vector through vector embedding of model hidden size before attention runs.
- Tokenizers overview
How tokenizers turn raw text into reusable pieces before embeddings, attention, and next-token prediction begin.
- Tokens Per Second
Tokens per second (tokens/s, tok/s, or TPS) is a throughput rate: how many model tokens a serving system generates per second over the measurement window you choose.
- Transformer
A model family built from stacked attention and feed-forward blocks that mix information across token positions in parallel.
- Transformer architecture
How attention, feed-forward layers, normalization, residuals, and position information repeat inside each decoder-style transformer block.
- Video generation
Models that produce moving visual sequences by generating or refining frames—or visual tokens arranged over time—while keeping motion, identity, and appearance coherent from one moment to the next.
- Visual tokenization
How images and video frames become patches, discrete codes, or latent tokens so sequence-based models can read visual data.
- Why long context is hard
Why stretching sequence length strains attention compute, KV-cache memory, position schemes, and retrieval quality even when a model advertises a large context window.
- World Model
A model family that learns environment dynamics or state transitions so it can predict or simulate what happens next.