Check out example codes for "bootstrap 4 checkbox". It will help you in understanding the concepts better.

Code Example 1

<div class="form-check form-check-inline">
      <input id="checkbox3" type="checkbox" checked="checked">
      <label for="checkbox3">Checkbox checked</label>
    </div>

Code Example 2

<div class="form-check">
  <input type="checkbox" class="form-check-input" id="exampleCheck1">
  <label class="form-check-label" for="exampleCheck1">Check me out</label>
</div>

Code Example 3

<div class="form-group">
    <label for="exampleFormControlTextarea1">Example textarea</label>
    <textarea class="form-control" id="exampleFormControlTextarea1" rows="3">

Code Example 4

<div>
  <div class="row">
    <div class="form-check form-check-inline">
      <input id="checkbox2" type="checkbox">
      <label for="checkbox2">Checkbox not checked</label>
    </div>
    <div class="form-check form-check-inline">
      <input id="checkbox3" type="checkbox" checked="checked">
      <label for="checkbox3">Checkbox checked</label>
    </div>
  </div>
</div>

Code Example 5

<form action="/action_page.php">
  <div class="form-group">
    <label for="email">Email address:</label>
    <input type="email" class="form-control" id="email">
  </div>
  <div class="form-group">
    <label for="pwd">Password:</label>
    <input type="password" class="form-control" id="pwd">
  </div>
  <div class="checkbox">
    <label><input type="checkbox"> Remember me</label>
  </div>
  <button type="submit" class="btn btn-default">Submit</button>

 </form>

Code Example 6

<div class="form-check form-check-inline">
  <input class="form-check-input" type="checkbox" id="inlineCheckbox1" value="option1">
  <label class="form-check-label" for="inlineCheckbox1">1</label>
</div>
<div class="form-check form-check-inline">
  <input class="form-check-input" type="checkbox" id="inlineCheckbox2" value="option2">
  <label class="form-check-label" for="inlineCheckbox2">2</label>
</div>
<div class="form-check form-check-inline">
  <input class="form-check-input" type="checkbox" id="inlineCheckbox3" value="option3" disabled>
  <label class="form-check-label" for="inlineCheckbox3">3 (disabled)</label>
</div>

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