@ChristinaCaMay 02.2014 — #Image optimization is all about adding image to alt tags. Image can be an effective SEO source. If a site contain too many images, one can add alt tags in images using keywords in alt tags. Adding alt tags in images is like showing search engine bots the name of image. You can also show the images of your site from different angles, in different sizes.
@Sup3rkirbyMay 02.2014 — #Image Optimization, is really about using the proper image formats and compressing images to reduce file size (and thus increase page speed, which Google likes from an SEO standpoint).
As far as alt tags go, they are certainly useful for SEO as they allow you to associate keywords with images and can provide relevant text/descriptions for cases where the image cannot be displayed. But more to the point, alt tags are actually required for your HTML to be considered valid, so it should really become a standard practice to always use them when adding images.
Another useful optimization tip is to make the filenames of images relevant. So if you have a picture of three tomatoes in a garden, the image name should be something like "[I]3-tomatoes-garden.jpg[/I]" (more or less). The actual filename of the image can help improve SEO rankings as it can provide relevant keywords/descriptors to a search engine when being indexed.
Lastly, as far as your question, [B][I]"how do i do that plz?"[/I][/B] goes, the alt tag is an HTML attribute that goes inside of an [B]<img>[/B] tag, like so: [code=html] <img src="3-tomatoes-garden.jpg" alt="Three tomatoes in a garden"> [/code]
@RoopatgMay 03.2014 — #Image optimization is using the most compressed (smallest file size) yet visually acceptable image in the proper file format for the specific role of the image.