We use html tag textarea for input of long text e.g. in contact form, we use textarea tag for message (which may have long text), similarly in admission form, we use textarea tag for long description.

Tag textarea syntax are;

<textarea>Some text which is already defined</textarea>

We may need text editor with extra functions to write text with images and some others animations etc. For, we use some JavaScript code to make same html textarea as Text Editor.

<script src="https://cloud.tinymce.com/stable/tinymce.min.js"></script>
<script>tinymce.init({ selector:'textarea' });</script>