When you see a picture of a baby crying, you instantly recognize what’s going on in the picture.
The problem is, this instant recognition isn’t possible for search engine spiders at this time. Instead, you must help the spiders understand each of your images with alt text.
What is image alt text?
The short answer is, it’s the text that the search engine uses to understand images.
To include it, you simply add alt="this is your alt text" to your image tag. Here’s an example:
<img src="baby-crying.jpg" alt="Baby Crying" />