Glossary
This glossary provides definitions of the key concepts in Kubernetes to help you develop a basic understanding of how Kubernetes works and to understand the use of certain terms in the documentation:
Cluster Networking
Refers to the highly integrated communication between containers, pods, pods and services, or from external sources to services.
CPU
The central processing unit of a computer, which is responsible for executing programme instructions.
Environment Variable
An environment variable is a key-value pair in memory that is used to store an application’s configuration details.
Feature Gate
Feature gates are key-value pairs that describe functions in Kubernetes.
Hash
A hash is a fixed-length string created by applying a hash function to data. Hashes are frequently used to encrypt SSH keys or to generate unique numerical values that serve as identifiers for data resources.
Health Check
A health check is a regular HTTP or TCP request carried out to ensure that a service is functioning correctly.
High Availability (HA)
An approach to infrastructure design that aims to reduce downtime and eliminate single points of failure.
High-availability control plane
A control plane that has multiple replicas of each component to ensure higher availability.
Image
A container image is a static file that contains executable code.
IP
The Internet Protocol is a communication protocol used to connect computers, particularly via the Internet.
Keep-Alive
A signal sent from one device to another to maintain the connection.
kubectl
A command-line interface (CLI) for executing commands on Kubernetes clusters.
Load Balancer
A load balancer that distributes data traffic across a group of servers in order to improve the stability and responsiveness of an application.
Logs
Standard output logs containing information about activities relating to your application.
Machine Type
Refers to the virtual hardware resources used by a VM instance.
Namespace
A collection of resources that contain one or more functions within a Kubernetes cluster.
Node Plan
The hardware configuration for a node’s specifications.
Node Pool
A group of nodes with the same configuration within a cluster.
Pod
The smallest computing unit managed and deployable by Kubernetes.
Port
A communication endpoint on a network connection, identified by a port number for each transport protocol.
Proxy
A computer or software system that acts as an intermediary between a client device and another server.
RBAC
Role-Based Access Control, a method of restricting network access based on a user’s role within an organisation.
SSL Certificates
A digital document that describes the identity of a website.
Sticky Session
A process in which the load balancer establishes a network connection with a user for the duration of a session.
Surge Upgrade
An upgrade process in which up to 10 additional nodes are created during a cluster upgrade.
Tag
Keywords that are assigned to resources and assist with the management, organisation and implementation of actions relating to those resources.
TCP
The Transmission Control Protocol, a standard for exchanging messages over a network.
TTL
Time to Live: the lifetime of a packet in a network before it is discarded by a router.
UDP
The User Datagram Protocol, a protocol for low-latency connection-oriented communication between applications.
Worker Node
A node that runs applications within a cluster and reports to a control plane.