Terms starting with E

10 of 250 glossary terms. Each entry links to its own page with why it matters and where it fits.

Definitions here are written for engineers, not grammarians: what the term means, why it matters when it comes up, and where it sits in the curriculum — most term pages name the lessons that lean on the concept, so you can jump from a definition straight to the teaching. Use the letter bar below to move through the alphabet, or press the slash key to search the whole corpus directly.

Every entry carries three things besides the definition: the plain aliases it travels under (listed as “also”), a category tag for which stretch of the curriculum it belongs to, and the cross-references that place it next to its neighbors — the terms you would meet in the same lesson. A term earns a page here only when a lesson in the curriculum actually uses it, so the corpus stays the shape of the material instead of the shape of a dictionary.

One honest way to use this page: read down the list of entries below and note every term you could not define in a sentence if a colleague asked. That list — not the whole letter — is your revision list, and each entry links to the reading that closes the gap.

Early Fusion
Multimodal systems
Combining raw or low-level representations from several modalities before most task-specific modeling occurs.
Eigenvalue
Math & training
A scalar that describes how a linear transformation scales a corresponding nonzero eigenvector without changing its direction. In covariance-matrix PCA, larger eigenvalues correspond to directions with more variance.
Embedding
Data & representations
A learned mapping from discrete items (words, images, users) to dense vectors in continuous space, where similar items end up close together
Encoder
Models & inference
A component that transforms input into a representation. A transformer encoder commonly uses non-causal self-attention, subject to any masks, so each position can incorporate context from across the input.
Epoch
Math & training
One traversal of the defined training dataset. In distributed or sampled training, the exact implementation of an epoch depends on the data loader and sampling policy.
Error Budget
Reliability & operations
The amount of unsuccessful service allowed by a service-level objective over its measurement window before the objective is exhausted.
Eval Set
also: Evaluation set
Evaluation & safety
A versioned collection of inputs, expected properties, scoring rules, and metadata used to measure an AI system against a defined capability or risk.
Evaluation (Eval)
also: Eval
Evaluation & safety
A defined process for measuring model or system behavior on representative tasks using explicit success criteria, data, scorers, and review procedures.
Exact Match (EM)
Evaluation & safety
A metric that counts an output as correct only when its normalized representation exactly equals an accepted reference answer.
Expert Parallelism
Infrastructure & serving
Distributing mixture-of-experts subnetworks across devices and routing each token's activations to the devices that host its selected experts.