# Core concepts

Core concepts explain the internal structure of HedgeDoc by providing
background information and explanations. They are especially useful for contributing to HedgeDoc.

<!-- markdownlint-disable no-inline-html -->
<div class='topic-container'>
    <a href='/concepts/notes/'>
        <div class='topic'>
            <span>📝</span>
            <span>Notes</span>
        </div>
    </a>
    <a href='/concepts/media/'>
        <div class='topic'>
            <span>📸</span>
            <span>Media</span>
        </div>
    </a>
    <a href='/concepts/user-profiles/'>
        <div class='topic'>
            <span>🙎</span>
            <span>User Profiles</span>
        </div>
    </a>
    <a href='/concepts/config/'>
        <div class='topic'>
            <span>🛠️</span>
            <span>Config</span>
        </div>
    </a>
    <a href='/concepts/api-auth/'>
        <div class='topic'>
            <span>🤖️</span>
            <span>API Auth</span>
        </div>
    </a>
    <a href='/concepts/events/'>
        <div class='topic'>
            <span>🎩</span>
            <span>Events</span>
        </div>
    </a>
</div>
<!-- markdownlint-enable no-inline-html -->