A creative tag is a piece of code that is used to display an advertisement on a website or app. Creative tags are often used in display advertising and video advertising, and may be provided by the advertiser or the ad agency running the ad campaign.

Creative tags are usually placed on the webpage or app where the ad is to be displayed, and are used to retrieve and display the ad from the advertiser's ad server. Creative tags may include a range of information, such as the size and format of the ad, and the target audience for the ad.

In addition to displaying the ad, creative tags may also be used to track the performance of the ad and to collect data on how users interact with the ad. This data may be used to optimize the ad campaign and to improve the overall effectiveness of the ads.