How to save images for web in Photoshop CS5
You can optimize or compress your pictures using Photoshop CS5. By compressing the images you can able to upload or share as many pictures as you want due to it's size you can set these compressed pictures as on your website as background or share on email with your friend's and family.
Why we need to make images for web the answer is because most free webhosting services can't support big file sizes and you have to wait to upload the files on web server and it, takes time to download form a web server meanwhile your visitor may leave your website. That's why we reduce the file size or compress Photos, or Pictures so that they shall be easily uploaded / download on server. By compressing the size of picture it takes less time to get downloaded from server.
Let’s start the process of saving this Picture as web ready JPEG image. Go into File Menu and Choose. Save for web and devices Or use Shortcut key. You can use Photo for your websites as background or upload on internet as web Picture.
For Mac ,Cmd+Shift+Option+S ,For Windows ,Alt+Shift+Ctrl+S
That brings up the save web dialogue box,
switch to 4up,