Bot traffic refers to traffic on a website or app that is generated by automated software, rather than by human users. In the context of display advertising, bot traffic is a concern because it can inflate the number of impressions and clicks on an ad, leading to higher advertising costs for the advertiser. Bot traffic can be generated by a variety of sources, including malicious actors who use bots to click on ads and generate fake traffic, as well as legitimate sources such as search engine crawlers and social media bots. Advertisers can use a variety of techniques to identify and filter out bot traffic, such as analyzing the behavior and characteristics of visitors to their website or app, and working with third-party companies that specialize in detecting and blocking bot traffic.