You have several ad types / styles to choose from, when you are ready to select the adsense layout for your adsense code.
In general Google Adsense offers you the choice of displaying text ads or picture ads, or a combination of both.
It is entirely up to you to choose what Google Adsense ad format you want to display.
Below is a overview of the current Google Adsense formats available.
Adsense Leader board Text 728 width x 90 height.
Recommended positions: page top, page middle, page bottom
Adsense Leader board Picture 728 width x 90 height.
Recommended positions: page top, page middle, page bottom
Adsense Banner Text 468 width x 60 height.
Recommended positions: page top, page middle, page bottom
Adsense Banner Picture 468 width x 60 height.
Recommended positions: page top, page middle, page bottom
Small Banner Text 234 width x 60 height.
Recommended positions: page top, page middle
Button text 125 width x 125 height.
Recommended positions: page left, page right, page middle
Skyscraper Text 120 width x 600 height.
Recommended positions: page left, page right
Skyscraper Picture 120 width x 600 height.
Recommended positions: page left, page right
Skyscraper Text 160 width x 600 height.
Recommended positions: page left, page right
Banner text 120 width x 240 height.
Recommended positions: page left, page right, page mid
Medium Rectangle text 300 width x 250 height
Recommended positions: page left, page right
Medium Rectangle Picture 300 width x 250 height
Recommended positions: page left, page right
Big Rectangle Text 336 width x 280 height
Recommended positions: page left, page right
Square Text 250 width x 250 height
Recommended positions: page left, page right
Small Square Text 180 width x 150 height.
Recommended positions: page top, page middle, page bottom
Adlinks Text 120 width x 90 height - shows 5 ads
Recommended positions: page top, page middle, page bottom
Adlinks Text 120 width x 90 height - shows 4 ads
Recommended positions: page top, page middle, page bottom
Adlinks Text 160 width x 90 height - shows 5 ads
Recommended positions: page top, page middle, page bottom
Adlinks Text 160 width x 90 height - shows 4 ads
Recommended positions: page top, page middle, page bottom
Adlinks Text 180 width x 90 height - shows 5 ads
Recommended positions: page top, page middle, page bottom
Adlinks Text 180 width x 90 height - shows 4 ads
Recommended positions: page top, page middle, page bottom
Adlinks Text 200 width x 90 height - shows 5 ads
Recommended positions: page top, page middle, page bottom
Adlinks Text 200 width x 90 height - shows 4 ads
Recommended positions: page top, page middle, page bottom