Glossary

Abstract class

A class defining shared behaviour and possibly steps implemented by subclasses. It cannot be instantiated directly and is not required for every composition.

Abstract Factory

A creation contract for a family of collaborating products, such as a client and its serializer. One object usually needs only a simple factory.

Abstract Syntax Tree

AST

Abstract Syntax Tree

A tree representing code structure. AST analysis distinguishes code from text; it does not by itself prove correct runtime behavior.

ACID

ACID

Atomicity, Consistency, Isolation, Durability

Transaction properties: atomicity, consistency, isolation and durability. Exact guarantees depend on the database and configuration; ACID does not automatically cover external HTTP.

Acknowledgement

ACK

Acknowledgement

Confirmation of receipt or completion under a particular protocol. Losing an ACK can cause redelivery even after the effect occurred.

Active Record

Combines represented record data with persistence behaviour. It differs from Data Mapper; complex rules and transaction scope still need deliberate design.

Adapter

Adapts a foreign interface, units and errors to a client contract. It protects a boundary rather than spreading vendor formats through the domain.

Admission controller

A mechanism validating or mutating a Kubernetes API request before object persistence, after authentication and authorization. It does not replace application runtime tests.

age encryption

age is a tool name, not an acronym.

A recipient-key file encryption tool. SOPS can use age to protect the data key; store private keys separately from the encrypted repository.

Agent Client Protocol

ACP

Agent Client Protocol

A protocol connecting an editor with a coding agent. It does not itself grant permissions: control access to files, commands and secrets.

AI agent

A system using a model to choose subsequent steps or tools. Permissions, limits and approval of effects must be enforced outside prompt text.

AI evaluation

Testing an AI solution against defined cases and criteria. Separate format validity, content quality, safe refusal, cost and latency.

Amazon API Gateway

Managed API gateway with backend integrations and traffic controls. Gateway authorization does not remove application resource-ownership checks.

Amazon Aurora

Managed relational engine compatible with particular MySQL or PostgreSQL variants. Compatibility does not imply identical extensions, operations or limits.

Amazon CloudFront

Content delivery with caches near users. Cache keys and header policies determine safe response sharing; private data must not enter a shared cache.

Amazon CloudWatch

Metrics, logs and alarms for resources and applications. An alarm needs a meaningful signal and an operator response. It differs from CloudTrail API auditing.

Amazon DynamoDB

Managed key-value and document database. Design keys and access patterns before queries; copying a relational model unchanged does not preserve its behavior.

Amazon EBS

EBS

Elastic Block Store

Block volumes for EC2 instances. A volume snapshot and restore do not prove database consistency without an appropriate backup procedure.

Amazon EC2

EC2

Elastic Compute Cloud

AWS compute-instance service. With virtual machines, responsibilities include operating systems, updates, application configuration and required resources and permissions.

Amazon ECS

ECS

Elastic Container Service

ECS manages AWS container tasks; Fargate supplies compute without user-managed hosts. It is a different model from Kubernetes, not another name for it.

Amazon EFS

EFS

Elastic File System

Managed shared file storage. Semantics, latency and permissions differ from local disks and S3 objects.

Amazon ElastiCache

Managed in-memory data/cache layer. Durability and failure behavior depend on configuration and engine; do not assume a cache is the authoritative durable store.

Amazon EventBridge

Routes events between producers and consumers using rules. Rule matching, retries and undelivered events need design; it is not a universal queue replacement.

Amazon Machine Image

AMI

Amazon Machine Image

An EC2 machine image containing an operating system and configuration. It is not a container image; match architecture and region.

Amazon Resource Name

ARN

Amazon Resource Name

An AWS resource identifier conveying resource type and scope. Use it deliberately in policies; broad wildcards can grant more access than intended.

Amazon Route 53

DNS and DNS response routing. Cached records can delay visibility of a change. Healthy DNS does not prove that certificates and the backend work.

Amazon S3

S3

Simple Storage Service

AWS object storage used for artifacts and backups, among other purposes. Define access, versioning, retention and recovery; a bucket alone is not a backup strategy.

Amazon SES

SES

Simple Email Service

An email sending and receiving service. Verify sender identity and handle bounces and sending reputation. API success does not prove inbox delivery.

Amazon SNS

SNS

Simple Notification Service

Publishes messages to a topic and fans them out to subscribers, including multiple SQS queues. It does not automatically replace a work queue or consumer idempotency.

AP system

AP

Availability and Partition tolerance

In CAP discussions, a system that responds during a network partition while allowing loss of linearizable consistency. Recovery requires conflict-resolution rules; AP does not guarantee flawless availability of the whole product.