Amazon EKS — Glossary

Key terms and definitions used throughout this Amazon EKS tutorial.

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A

Term	Definition
Access Entry	EKS-native API for granting IAM principals access to a cluster (replacement for aws-auth ConfigMap)
Add-on	Pre-configured operational software managed by EKS (e.g., VPC CNI, CoreDNS, kube-proxy)
ALB	Application Load Balancer — Layer 7 load balancer for HTTP/HTTPS traffic
ArgoCD	GitOps continuous delivery tool for Kubernetes
aws-auth ConfigMap	Legacy method of mapping IAM identities to Kubernetes RBAC (in kube-system namespace)

C

Term	Definition
Cluster Autoscaler	Kubernetes add-on that adjusts node group size based on pending pods
ConfigMap	Kubernetes object for storing non-sensitive configuration data
Control Plane	The managed EKS components (API server, etcd, scheduler, controller manager) — AWS manages these
CoreDNS	DNS server for Kubernetes service discovery — runs as a Deployment in kube-system
CrashLoopBackOff	Pod status indicating the container keeps crashing and Kubernetes is backing off restarts

D

Term	Definition
DaemonSet	Ensures a copy of a pod runs on every (or selected) node
Deployment	Kubernetes resource for managing stateless application replicas

E

Term	Definition
EBS CSI Driver	Add-on enabling Kubernetes to use Amazon EBS for persistent storage
ECR	Elastic Container Registry — AWS managed Docker image registry
EKS	Elastic Kubernetes Service — AWS managed Kubernetes
ENI	Elastic Network Interface — each pod IP comes from an ENI in the VPC (via VPC CNI)
eksctl	Official CLI tool for creating and managing EKS clusters

F

Term	Definition
Fargate	Serverless compute for EKS — AWS manages the nodes
Fargate Profile	Defines which pods run on Fargate based on namespace and label selectors
Fluent Bit	Lightweight log processor/forwarder — commonly used for container log shipping
Flux	GitOps toolkit for Kubernetes — alternative to ArgoCD

H

Term	Definition
Helm	Package manager for Kubernetes — uses charts to define, install, and upgrade applications
HPA	Horizontal Pod Autoscaler — scales pod replicas based on metrics

I

Term	Definition
IAM	Identity and Access Management — AWS authentication and authorization service
Ingress	Kubernetes resource defining external access to Services (usually via ALB)
IRSA	IAM Roles for Service Accounts — maps Kubernetes service accounts to IAM roles for AWS API access

K

Term	Definition
Karpenter	Node provisioner that launches right-sized compute in response to pending pods
Kubecost	Cost monitoring tool for Kubernetes workloads
kubectl	Command-line tool for interacting with Kubernetes API
kubelet	Agent running on each node that manages pod lifecycle
kube-proxy	Network component on each node that implements Kubernetes Service networking

L

Term	Definition
LimitRange	Sets default and maximum resource limits per namespace

M

Term	Definition
Managed Node Group	EKS-managed EC2 instances with automated provisioning, updates, and lifecycle

N

Term	Definition
Namespace	Virtual cluster partition for resource isolation and RBAC
NAT Gateway	AWS service enabling outbound internet access from private subnets
NetworkPolicy	Kubernetes resource controlling pod-to-pod network traffic
NLB	Network Load Balancer — Layer 4 load balancer for TCP/UDP traffic
Node	Worker machine (EC2 instance) running pods

O

Term	Definition
OIDC	OpenID Connect — identity protocol used by EKS for IRSA
OOMKilled	Container terminated because it exceeded its memory limit (exit code 137)
OpenCost	Open-source Kubernetes cost monitoring (CNCF project)

P

Term	Definition
PDB	Pod Disruption Budget — limits voluntary disruptions to maintain availability
PersistentVolume (PV)	Cluster-level storage resource backed by EBS, EFS, or other storage
PersistentVolumeClaim (PVC)	Pod’s request for persistent storage
Pod	Smallest deployable unit in Kubernetes — one or more containers sharing network and storage
Prefix Delegation	VPC CNI feature assigning /28 prefixes instead of individual IPs, enabling more pods per node

R

Term	Definition
RBAC	Role-Based Access Control — Kubernetes authorization model using Roles and RoleBindings
ResourceQuota	Limits total resource consumption per namespace

S

Term	Definition
Secret	Kubernetes object for storing sensitive data (passwords, tokens)
SecurityContext	Pod/container-level security settings (runAsUser, capabilities, readOnlyRootFilesystem)
Service	Kubernetes abstraction providing stable network endpoint for pods (ClusterIP, NodePort, LoadBalancer)
ServiceAccount	Kubernetes identity for pods to authenticate to the API server and AWS (via IRSA)
StatefulSet	Kubernetes resource for managing stateful applications with stable identity and persistent storage
StorageClass	Defines how persistent volumes are dynamically provisioned (gp3, io2, efs)

T

Term	Definition
Taint	Node attribute that repels pods unless they have a matching toleration
Terraform	Infrastructure as Code tool by HashiCorp — commonly used for EKS cluster provisioning
Toleration	Pod attribute allowing scheduling on tainted nodes
TopologySpreadConstraints	Rules for distributing pods across topology domains (AZs, nodes)

V

Term	Definition
VPA	Vertical Pod Autoscaler — adjusts pod CPU/memory requests based on historical usage
VPC	Virtual Private Cloud — isolated AWS network for your resources
VPC CNI	AWS EKS networking plugin that assigns VPC IP addresses directly to pods

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