Grupos de caixas de seleção e botões de opção

<label>
  <input type="checkbox" name="terms" value="agreed"> I agree to the Terms
</label>

<!-- Each checkbox is independent -->
<!-- checked attribute = pre-checked -->
<input type="checkbox" name="newsletter" value="yes" checked>

<form>
  <input type="checkbox" name="hobby" value="reading"> Reading<br>
  <input type="checkbox" name="hobby" value="coding"> Coding<br>
  <input type="checkbox" name="hobby" value="gaming"> Gaming<br>
</form>
<!-- If reading and coding are checked:
     hobby=reading&hobby=coding -->
<!-- Unchecked boxes send nothing -->

<fieldset>
  <legend>Select your interests</legend>

  <label><input type="checkbox" name="interest" value="html"> HTML</label>
  <label><input type="checkbox" name="interest" value="css"> CSS</label>
  <label><input type="checkbox" name="interest" value="js"> JavaScript</label>
  <label><input type="checkbox" name="interest" value="python"> Python</label>
</fieldset>

<fieldset>
  <legend>Preferred plan</legend>

  <label><input type="radio" name="plan" value="free"> Free</label>
  <label><input type="radio" name="plan" value="pro"> Pro</label>
  <label><input type="radio" name="plan" value="enterprise"> Enterprise</label>
</fieldset>
<!-- All radios in a group share the same name attribute -->
<!-- Selecting one deselects the others -->

<fieldset>
  <legend>Skill level</legend>
  <label><input type="radio" name="level" value="beginner" checked> Beginner</label>
  <label><input type="radio" name="level" value="intermediate"> Intermediate</label>
  <label><input type="radio" name="level" value="advanced"> Advanced</label>
</fieldset>

<label class="custom-check">
  <input type="checkbox" name="agree">
  <span class="checkmark"></span>
  I agree
</label>

/* Hide native input, style the span: */
.custom-check input { opacity: 0; width: 0; }
.checkmark {
  width: 1.25rem; height: 1.25rem;
  border: 2px solid #ddd; border-radius: 3px;
  display: inline-block; vertical-align: middle;
}
.custom-check input:checked + .checkmark { background: #0070f3; }

<input type="checkbox" id="select-all">

<script>
// Set via JavaScript only -- no HTML attribute
document.getElementById('select-all').indeterminate = true;
// Visually shown as a dash (−) in most browsers
// Used for "select all" when some children are checked
</script>

<fieldset>
  <legend>Gender</legend>
  <label><input type="radio" name="gender" value="m" required> Male</label>
  <label><input type="radio" name="gender" value="f" required> Female</label>
  <label><input type="radio" name="gender" value="nb" required> Non-binary</label>
  <label><input type="radio" name="gender" value="prefer_not" required> Prefer not to say</label>
</fieldset>

<!-- The value sent when checked: -->
<input type="checkbox" name="subscribe" value="yes">
<!-- Submits: subscribe=yes when checked -->
<!-- If value is omitted, default value is 'on' -->

<!-- JavaScript checked state: -->
const cb = document.querySelector('input[name="subscribe"]');
console.log(cb.checked);    // true or false
console.log(cb.value);      // 'yes' (always, even when unchecked)

<label>
  <input type="checkbox" id="select-all"> Select all
</label>
<fieldset id="items">
  <label><input type="checkbox" class="item" value="1"> Item 1</label>
  <label><input type="checkbox" class="item" value="2"> Item 2</label>
  <label><input type="checkbox" class="item" value="3"> Item 3</label>
</fieldset>
<script>
document.getElementById('select-all').addEventListener('change', function() {
  document.querySelectorAll('.item').forEach(cb => cb.checked = this.checked);
});
</script>