General HTML structure is the same throughout the template. Here is the Folder structure.

HTML Folder structure for Frest assets.

frest-clean-bootstrap-admin-dashboard-template
├── html
|   ├── ltr
|   |   ├── vertical-menu-template
|   |   ├── vertical-menu-template-dark
|   |   ├── vertical-menu-template-semi-dark
|   |   ├── vertical-menu-boxicons-template
|   |   ├── horizontal-menu-template
|   |   └── horizontal-menu-template-dark
|   └── rtl

Following is the details of all html folders.

<nav class="header-navbar main-header-navbar navbar-expand-lg navbar navbar-with-menu fixed-top">
    <div class="navbar-wrapper">
        <div class="navbar-container content">
            <div id="navbar-mobile" class="navbar-collapse">
                ...
            </div>
        </div>
    </div>
</nav>

<div class="main-menu menu-fixed menu-light menu-accordion menu-shadow" data-scroll-to-active="true">
    <!-- main menu header -->
    <div class="navbar-header">
        ...
    </div>
    <!--/ main menu header -->

    <!-- shadow below menu header -->
    <div class="shadow-bottom"></div>
    <!--/ shadow below menu header -->

    <!-- main menu content -->
    <div class="main-menu-content">
        <ul class="navigation navigation-main" id="main-menu-navigation" data-menu="menu-navigation" data-icon-style="lines">
            ...
        </ul>
    </div>
    <!--/ main menu content -->
</div>

<div class="app-content content">
    <!-- create overlay over content area -->
    <div class="content-overlay"><div>
    <!--/ create overlay over content area -->

    <!-- content area -->
    <div class="content-wrapper">
        <div class="content-header row">
            ...
        </div>
        <div class="content-body">
            ...
        </div>
    </div>
    <!--/ content area -->
</div>

<footer class="footer footer-static footer-light">
    ...
</footer>