The below image has been inserted through Markdown and is its native size of 600x600px.
The below image has been inserted through HTML and is its native size of 600x600px.
<img src="{{ site.baseurl }}/assets/img/rainbow-color-square-hi.png" alt="600x600 HTML" />
The below image has been inserted through HTML, but has been resized to 300 in height only.
<img src="{{ site.baseurl }}/assets/img/rainbow-color-square-hi.png" height="300" alt="300x300 HTML" />
The below image has been inserted through HTML, but has been resized to 300 in both height and width.
<img src="{{ site.baseurl }}/assets/img/rainbow-color-square-hi.png" width="300" height="300" alt="300x300 HTML" />
The below image has been inserted through HTML, but has been resized to 300 in width only.
<img src="{{ site.baseurl }}/assets/img/rainbow-color-square-hi.png" width="300" alt="300x300 HTML" />