Tag is a label attached to an email-platform contact to organize records, record interests or support segmentation and automation.
It matters because email is one of the few channels a business can own directly. Strong email fundamentals improve trust, deliverability, segmentation, and long-term lead nurturing.
Example
An email contact receives the tag ‘attended-webinar’ after an event. The team can use that label to organize follow-up audiences; the tag is a contact label, not a website tracking script.