The words nobody explains to you

Every definition stands on its own. You can land here from a link, read three lines, and leave.

Instruction file

A plain text file sitting in your project folder. Your AI reads all of it every time it starts, before you say anything. You write down what your project is and how you want to work.

Your tool usually calls it CLAUDE.md, AGENTS.md or .cursorrules. Same file, different name.

Token

The unit your subscription counts. One token is roughly three quarters of a word. When your AI writes a long answer or re-reads a big file, it burns tokens, and that is what fills your meter.

On your usage page. You never need to count them yourself.

Context

Everything your AI has in front of it as it answers: your request, the files it opened, the current conversation. Its memory stops there. Close the window and all of it is gone.

When it "forgets" what you agreed yesterday, that is context it no longer has.

Terminal

A black window where you type commands, with no buttons and no mouse. It is a developer tool. Many competing kits assume you already know how to use one.

Called "Command Prompt" on Windows, "Terminal" on Mac.

Host

The company that keeps your site files on its machines and serves them to visitors. Without a host, your site exists on your computer and nowhere else.

Vercel, Netlify, Cloudflare are hosts. It is what you pay monthly to stay online.

Go live (deploy)

Sending the current version of your site to the host so visitors can see it. Until you do, your changes exist only on your own machine.

The technical word is "deploy". It is the button that makes your work public.

Version history (Git)

A tool that photographs your project at every step. If the AI breaks something, you go back to the previous photo with one command and lose nothing else.

Each photo is called a "commit". The place they are stored is called a "repository".

Guardrail

An automatic check that runs on its own and stops your AI before an irreversible move: deleting a folder, overwriting your work. It cannot talk its way past it.

Tools call it a "hook". It protects you while your back is turned.

Indexing

The moment Google records your page in its list. Until a page is indexed it shows up in no search result at all, even if you type its exact title.

A brand new page takes a few days to a few weeks to get indexed.

Crawler

A program that walks the web and reads pages on behalf of a search engine or an AI. Block it and your site can neither appear nor be cited.

The robots.txt file is the list of who is allowed in.

Domain name

The address people type to reach you, for example my-site.com. You rent it yearly. It stays yours as long as you renew it, whoever your host is.

It is the one thing you must never let expire.

Tag

A small piece of invisible text in your page that tells search engines things: the title shown in Google, the language, the description. Visitors never see it.

When a tool says "your title tag is too long", that is what it means.