Check out example codes for "bootstrap file upload". It will help you in understanding the concepts better.
Code Example 1
<form>
<div class="form-group">
<label for="exampleFormControlFile1">Example file input</label>
<input type="file" class="form-control-file" id="exampleFormControlFile1">
</div>
</form>
Code Example 2
<!-- HTML Code -->
<form class="md-form">
<div class="file-field">
<div class="btn btn-primary btn-sm float-left">
<span>Choose file</span>
<input type="file">
</div>
<div class="file-path-wrapper">
<input class="file-path validate" type="text" placeholder="Upload your file">
</div>
</div>
</form>
Code Example 3
<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 4
<div class="form-check form-check-inline">
<input id="checkbox3" type="checkbox" checked="checked">
<label for="checkbox3">Checkbox checked</label>
</div>
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