Writing Code: Tools, Languages & Building Blocks

Integrated Development Environment

An all-in-one app for writing, running and debugging code, such as IntelliJ or Visual Studio. Lighter-weight code editors like VS Code now do much the same job, and most have AI coding assistants built in.

Command Line Interface

Controlling software by typing text commands rather than clicking, very common in development.

Software Development Kit

A ready-made toolkit of code and documentation for building on a particular platform or service.

Application Programming Interface

A defined way for two pieces of software to talk to each other and exchange data.

Reusable code you plug in

A collection of pre-written code you drop into your project so you do not have to build everything from scratch. React is a well-known example.

A foundation to build on

A structured base of pre-built code that shapes how an app is built, such as Next.js, Angular or Django. Unlike a library, a framework sets the overall structure your code fits into.

Code your project relies on

An external library or package that your software needs in order to work.

Installs and tracks dependencies

A tool that installs and keeps track of the libraries a project depends on: npm, pnpm or bun for JavaScript, pip or uv for Python.

Publicly licensed code

Software published under a licence that lets anyone use, change and share the code. Licences vary and some carry obligations, so terms still need checking before commercial use.

Fault, and fixing it

A bug is a fault in the code; debugging is the work of finding and fixing it.

Tidy without changing behaviour

Improving the internal structure of code without changing what it actually does.

The two halves of an app

Frontend is the part users see and interact with; backend is the behind-the-scenes logic, servers and databases. Doing both is called 'full-stack'.

HyperText Markup Language / Cascading Style Sheets

The two core web languages: HTML gives a page its structure, CSS gives it styling and layout.

Technology stack

The combined languages, frameworks, databases, cloud services and tools used to build and operate a product.

Execution environment

The software environment in which a program actually runs, providing the services it needs while executing.

Application architecture styles

A monolith ships as one tightly connected application; microservices split business capabilities into smaller services that can be deployed independently.

EDA

A system design where producers publish events and independent consumers react to them, often asynchronously and close to real time.

Asynchronous messaging patterns

Ways for software components to exchange work or events without waiting for each other, reducing direct coupling between systems.

User Experience / User Interface

UI is what a person sees and operates; UX is the wider quality of their interaction and experience across the whole product or service.

PHP: Hypertext Preprocessor

An open-source scripting language commonly executed on a server to generate web pages, APIs and command-line programs.