A website waits to be found. Digital marketing goes out and finds people: Google and Meta ads, social media, email, and the content that feeds them. The firms on this page offer paid ads, social media or both, usually alongside the website itself.
They are a mixed group, and that is the point of looking closely. Some are full-service agencies that can act as your whole marketing department. Some specialise, in paid ads across Meta, Google and Amazon, or in display and streaming TV advertising. Others are design studios that will look after your social accounts. If you are comparing two, ask who will actually run your campaigns, how often you will hear from them, and what the monthly fee covers beyond the ad spend.