Check out example codes for "how to add custom snippets in emmet in visual studio code". It will help you in understanding the concepts better.

Code Example 1

<!-- hold the Left Shift key with the ! (exclamation mark) and press enter -->

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>

Code Example 2

"emmet.triggerExpansionOnTab": true

Code Example 3

"Console log": {
    "prefix": "clog",
    "body": "console.log('$1');",
    "description": "Log output to console"
}

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