Remarketing, also known as retargeting, is a strategic online advertising technique that allows businesses to reconnect with users who have previously interacted with their website or mobile app. By using cookies or pixels, remarketing tracks these users and displays targeted ads to them across various platforms and websites they visit. This approach aims to increase brand awareness, engagement, and conversions by reminding potential customers of products or services they have shown interest in, encouraging them to return and complete a desired action.