Glossary

Developer, DevOps & AI terms, explained plainly

Clear, no-jargon definitions of the concepts behind our courses — from containers and Kubernetes to RAG, agents and MCP. Each term links to a full explainer and the course that teaches it.

A

Agent memory

The ability of an AI agent to persist information across separate runs — recalling past context instead of starting blank each time — which is what makes long-running, resumable workflows possible.

AI agent

An AI system that does more than answer — it decides on and takes actions using tools (reading systems, searching docs, running commands) to accomplish a goal, usually in a loop.

API

An Application Programming Interface: a defined contract that lets one piece of software talk to another, exchanging structured requests and responses rather than screens meant for humans.

C

CI/CD

Continuous Integration and Continuous Delivery/Deployment: the practice of automatically building, testing, and shipping every code change through a pipeline, instead of releasing by hand.

Command line

The text interface (shell) where you type commands to control a computer directly — the foundational tool for Linux, servers, and every deployment workflow.

ConfigMaps and Secrets

Kubernetes objects for supplying configuration to containers — ConfigMaps for non-sensitive settings, Secrets for sensitive values like passwords and tokens — kept separate from the image.

Container

A lightweight, isolated package of an application and everything it needs to run, sharing the host’s kernel — not a full virtual machine, which makes it fast to start and cheap to run.

D

DNS

The Domain Name System: the internet’s directory that translates a human-friendly domain name into the IP address a browser actually connects to.

E

Environment variables

Named values set outside your code and read at runtime — the standard way to pass configuration and secrets to a program without hard-coding them.

Exit code

The number a program returns when it finishes: 0 means success, anything else signals a specific failure — the primary way scripts and orchestrators know whether a step worked.

F

File permissions

The Linux rules that control who can read, write, or execute a file or directory — the model behind most "permission denied" errors and a core part of server security.

G

Git branches and commits

A commit is a saved snapshot of your project; a branch is an independent line of commits. Together they let you version history and work on changes in isolation before merging.

H

HTTPS / TLS

HTTPS is HTTP encrypted with TLS, so traffic between browser and server is private and tamper-proof and the server’s identity is verified by a certificate.

I

Infrastructure as Code

Defining servers, networks, and services in version-controlled files instead of clicking through consoles — so environments are repeatable, reviewable, and rebuildable.

K

Kubernetes

An open-source system for running containers across many machines — scheduling them, restarting failures, scaling, and networking them together so applications self-heal and stay available.

Kubernetes Services

A stable network endpoint that routes traffic to a changing set of pods. ClusterIP exposes it inside the cluster, NodePort and LoadBalancer expose it outside.

M

MCP (Model Context Protocol)

An open protocol that lets AI applications connect to external tools and data through a standard interface, so one server of tools can be used by any compatible client.

Multi-agent system

Several specialised AI agents coordinating on a task — each with a focused role and limited tools — instead of one agent trying to do everything, enabling separation of duties and safer autonomy.

O

Object-oriented programming

A way of structuring code around objects — bundles of data and the methods that act on it — using classes and inheritance to build software that scales beyond a single script.

P

Pods, Deployments & ReplicaSets

A Pod is the smallest deployable unit in Kubernetes (one or more containers); a ReplicaSet keeps a set number of identical pods running; a Deployment manages ReplicaSets to roll out updates safely.

Program execution

What actually happens when you run a program — source is interpreted or compiled, loaded into memory as a process, and executed by the CPU — the mental model behind most runtime errors.

Prompt injection

An attack where malicious text hidden in an AI system’s input hijacks its instructions — the core security risk to understand before letting an AI agent read untrusted data or take actions.

PromQL

The Prometheus Query Language, used to turn raw time-series metrics into rates, aggregations, and alerts — the language behind every real monitoring dashboard.

R

RAG (Retrieval-Augmented Generation)

A technique that retrieves relevant documents and feeds them to a language model so its answers are grounded in your data and can be cited — rather than made up from training alone.

Reverse proxy

A server that sits in front of your applications, receiving client requests and forwarding them on — handling TLS, routing, and load balancing in one place. Nginx is the classic example.

S

SSH keys

A cryptographic key pair — a public key you share and a private key you keep — used to log in to servers and services securely without passwords.

T

Tool calling

The mechanism (also called function calling) that lets a language model invoke real functions — checking a system, querying a database, sending a request — turning a chatbot into an agent that can act.

V

Vector embeddings

Numeric representations of text (or other data) that place similar meanings close together in space, enabling semantic search — the retrieval half of a RAG system.

Virtual environments

Isolated per-project Python installations that keep each project’s dependencies separate, so packages for one project never conflict with another.

Learn these by building, not memorising

Every term here is something you build with, hands-on, in a BytExplorer course.