Many people are unaware of the importance of alt tags. They ignore it. It is one of the big mistake not attaching the alt tag with the image. Actually we use alt tags so to provide the visitor text along with the image. Alt tag is for such people who cant see the image in the browser because of some reason. If you are running a website then you should be familiar of the importance of alt tag.
Alt attribute is actually for providing the description of any image. If the image is not shown for some reason then the location of image can be found with the help of alt. with the help of alt tag the ranking of your site will be better. With the help of alt tag, your site will be visible in image search also.
Eg : <img src=“painting.gif” alt=“man painting”>
With out alt tag <img src=“painting.gif” >
If you will ever use any image for the next time then never forget to use alt tag. Alt tag should be related to the image.