Source: MarketingTerms.com

Banner Ad – a graphical web advertising unit, typically measuring 468 pixels wide and 60 pixels tall (i.e. 468×60).

Beyond the Banner – online advertising not involving standard GIF and JPEG banner ads.

Button Ad – a graphical advertising unit, smaller than a banner ad.

HTML banner – a banner ad using HTML elements, often including interactive forms, instead of (or in addition to) standard graphical elements.

Interstitial – an advertisement that loads between two content pages.

Pop-up Ad – an ad that displays in a new browser window.

Pop-under Ad – an ad that displays in a new browser window behind the current browser window.

Rectangle Ad – any one of the large, rectangular banner sizes suggested by the IAB.

Rich Media – new media that offers an enhanced experience relative to older, mainstream formats.

Skyscraper Ad – an online ad significantly taller than the 120×240 vertical banner.

Text Ad – advertisement using text-based hyperlinks.

Surround Session – advertising sequence in which a visitor receives ads from one advertiser throughout an entire site visit.

Vertical Banner – a banner ad measuring 120 pixels wide and 240 pixels tall.