Publishers can implement their own Ad Unit by creating from Google Adsense Account. Implement the code is just like copy past task. You need not to develop the script code for the appearance of the Ad, Adsense Team has already did it for the publishers. Earlier, there was only one choice of Ad Code to paste in the blogs and website. But, right now it has changed its trend with the introduction of the Async attribute in the Ad Code. At the time of coping the Ad Code to the clip board you can find Code Type, based on the selection from the Drop Down Box it will show the corresponding Ad Code.
Synchronous Ad Code
This is the default Code Type and it has been using since the beginning of the Google Adsense program. Most of the publishers are using the Synchronous Script to render the Ads, which reduces the performance of the whole blog or website. If the Ads serving server or network gets any problem, the Ad will not be available, and it makes trouble to the rest of the part of your website to display.
Asynchronous Ad Code
To wipe off this kind problem Adsense team has come up with new Ad Code called Asynchronous Script which is under Beta version. Whenever a webpage is loading that contains an Asynchronous Script code it will not troubles the other parts of the website to display, when there is problem with Ad Serving server. So, the visitors will not disappoint and love to come back again to your website. So, make your website or blog load faster with the new Google Adsense Asynchronous (Beta) Script.
Adding Asynchronous Ad Code in Google Blogger
Select the Asynchronous from the Drop Down Box and press