whats the function of ...alt=""/>

Answer 1

here is an example: <img src="ww.image.com" alt="your browser does not support this form">
the text will shown up when the browser not able to show the photo

Answer 2

its an alternative text which is shown when our image is unable to load.

Answer 3

you can type anything inside the double quotes as long as it is about that image

Answer 4

Is there an example?

Answer 5

the alt="" is used as a description of the picture and is helpful when the images do not load.
Suppose you want to display a picture of a Tree on your website. So you will add <img src="tree.jpg" alt="Image of A Tree"> in your HTML Code.
When someone will browse over the image, the text "Image of a Tree" will get displayed and he/she will come to know that the image is of a tree.
When you add any text into the alt field others can see that text on the image when browse over it. Hope You Understood :)