Check out example codes for "picture html". It will help you in understanding the concepts better.
Code Example 1
<picture>
<source srcset="mdn-logo-wide.png" media="(min-width: 600px)">
<img src="mdn-logo-narrow.png" alt="MDN">
</picture>
Code Example 2
<!--When the image is in the same folder as your html file-->
<img src="example.jpg">
<!--When the image is in a image folder-->
<img src="./image/example.jpg">
Code Example 3
<img src="image.jps">
//image.jpg is where you would put the inage source.
Code Example 4
<img src="img_girl.jpg" alt="Girl in a jacket" style="width:500px;height:600px;">
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