A first taste of the web

Ideas to remember

1. 01HTML is not a programming language; it describes the structure of a page with tags that open, close and nest without crossing.
2. 02Everything the visitor sees lives inside body; head holds information about the page, such as the title on the browser tab.
3. 03Lists use ul or ol with li items, images use img with src and alt, and links use a with href.
4. 04A CSS rule is a selector plus declarations of property: value; and it lives in its own file linked from the head.
5. 05JavaScript gives a page behaviour with let and const variables, functions that return a result, and console.log to check values.
6. 06The DOM is the live model of the page; getElementById and textContent let a click change what the visitor sees without a reload.

Words

<p>This is a paragraph.</p>

An opening tag, the content, and a closing tag with a slash; br and hr are empty tags with no closing partner.

<h1> to <h6>

Six heading sizes; pick the level for what it means, not for how big it looks.

p { color: green; }

Selector p, property color, value green; the semicolon at the end of each declaration matters.

let, const

let creates a variable whose value can change later; const creates one that must not.

document.getElementById

Fetches the element with that id so you have a handle to work with.

textContent

The property that reads or replaces the words inside an element; setting it changes the screen at once.