active fade class bootstrap4 code example
Example: fade in active in bootstrap meaning
<div class="tab-content">
<div class="tab-pane fade show active" id="home" role="tabpanel" aria-labelledby="home-tab">...</div>
<div class="tab-pane fade" id="profile" role="tabpanel" aria-labelledby="profile-tab">...</div>
<div class="tab-pane fade" id="messages" role="tabpanel" aria-labelledby="messages-tab">...</div>
<div class="tab-pane fade" id="settings" role="tabpanel" aria-labelledby="settings-tab">...</div>
</div>