AI From Zero to Builder
Glossary
Canonical, learner-first definitions for recurring terms used across the curriculum, labs, and project work.
Use this page when a technical word interrupts the lesson. Definitions are intentionally short: enough to recover the idea and continue learning, while the Lessons provide the deeper context.
A
- admission controlProduction
- A rule that decides whether new work may start now, wait in a queue, or be rejected based on available capacity and limits.
- agent harnessAgents
- Application code around an agent that manages state, tools, permissions, retries, traces, budgets, and other execution rules.
- artifactAgents
- A result produced by a task, such as a file, report, structured record, or other output that can be tracked separately from messages.
B
- backoffReliability
- Waiting longer before another retry so repeated failures do not cause a rapid retry loop.
- backpressureProduction
- Slowing or limiting new work when downstream parts of a system are already near capacity.
- blast radiusSecurity
- The amount of data, users, systems, or actions that one failure or compromised component could affect.
C
- canaryProduction
- A small early release that sends limited traffic to a candidate version before a wider rollout.
- capabilityProtocols
- A specific action, resource, interface, or skill that a system says it can provide.
- cardinalityObservability
- The number of distinct values or label combinations in a dataset or metric; very high metric cardinality can be expensive to store and query.
- cosine similarityRetrieval
- A similarity score that compares vector direction after accounting for vector length.
D
- data exfiltrationSecurity
- Protected information leaving a system and reaching a destination that is not authorized to receive it.
- data minimizationPrivacy
- Collecting, sending, and keeping only the data needed for a declared purpose.
- degraded modeProduction
- A reduced version of a service that keeps the most important work running when full capacity or functionality is unavailable.
- delegationAgents
- Giving a bounded subtask to another agent or worker while keeping limits on its tools, budget, authority, and expected result.
- dot productMath & retrieval
- A number produced by multiplying matching vector components and adding the results; it can reflect both alignment and vector magnitude.
- durable stateReliability
- State stored so it can still be recovered after a process, worker, or machine stops.
E
- embeddingRetrieval
- A vector representation that places items in a numeric space so useful relationships can be compared mathematically.
- evictionProduction
- Removing stored or cached data to free limited memory for other work.
H
- headroomProduction
- Capacity deliberately left unused during normal operation so the system can absorb bursts, retries, or failures.
I
- idempotency keyReliability
- A stable identifier that lets repeated attempts be recognized as the same intended operation instead of new operations.
- inferenceModels
- Running a trained model on input to produce predictions, scores, embeddings, or generated output.
J
- jitterReliability
- A small variation added to retry timing so many workers do not all retry at exactly the same moment.
K
- KV cacheProduction
- Stored attention key and value state from earlier tokens that lets later generation steps reuse work instead of recomputing all prior attention state.
L
- latencyProduction
- How long a request or operation takes from a chosen start point to a chosen completion point.
- least privilegeSecurity
- Giving a user, agent, tool, or process only the permissions and data access needed for its current job.
- load sheddingProduction
- Rejecting or dropping some lower-priority work when accepting everything would overload the system.
- localityProduction
- Keeping data close to the compute that uses it so transfers cost less time and bandwidth.
O
- observabilityObservability
- Collecting and connecting enough traces, metrics, and logs to explain how a system behaved without guessing.
- operation IDReliability
- An identifier for one intended operation that can connect retries, completion evidence, and audit records.
P
- p95Evaluation
- The 95th percentile: a value that 95% of measured observations are at or below.
- preemptionProduction
- Pausing or removing active work so limited resources can be given to other work.
- prefillProduction
- The generation phase that processes the input tokens already present before one-token-at-a-time decoding continues.
- principalSecurity
- The trusted user, service, or other identity on whose behalf an action would occur.
- provenanceEvidence
- Information about where a piece of data, result, or claim came from and how it reached the current system.
Q
- quantizationModels
- Representing model numbers with fewer bits or a more compact numeric format to reduce storage or computation costs, with possible quality and compatibility tradeoffs.
R
- reconciliationReliability
- Checking durable or external evidence to determine what actually happened before deciding whether to repeat an uncertain operation.
- rerankingRetrieval
- Scoring a smaller set of retrieved candidates more carefully to improve their final order.
- residual riskSafety
- Risk that still remains after the planned controls have been applied.
- rollbackProduction
- Routing or deploying future work back to an earlier known version after a candidate release fails its gates.
S
- sandboxSecurity
- An execution environment that limits what files, network destinations, devices, or resources a process can reach.
- schemaInterfaces
- A machine-readable description of the fields, types, and structure that data is expected to follow.
- side effectReliability
- A change outside the current computation, such as charging money, sending a message, deleting a file, or updating a record.
- sliceEvaluation
- A group of evaluation cases inspected separately because its behavior may matter on its own, such as one task type or risk category.
- spanObservability
- One timed operation inside a trace, such as queue wait, model inference, or a tool call.
- statelessProtocols
- Designed so one request carries the information needed at that boundary instead of depending on hidden per-session protocol state.
T
- tenantSecurity
- One customer, organization, or isolated account boundary in a system that serves multiple groups.
- thrashingProduction
- Repeatedly moving, evicting, or recomputing data so aggressively that the overhead reduces useful progress.
- threat modelSecurity
- A structured description of what must be protected, which actors and boundaries exist, how failure or attack could happen, and where controls should stop it.
- throughputProduction
- How much useful work a system completes per unit of time, such as requests or tokens per second.
- traceObservability
- A connected record of the operations that one request or task passed through.
- trust boundarySecurity
- A place where data or requests cross between components that should not automatically trust one another.
V
- vector normMath & retrieval
- A measure of vector length; in cosine similarity it is used to normalize magnitude.
- version preconditionReliability
- A rule that accepts an update only if the stored version still matches the version the writer previously read.