What is the difference between Campaign and salesforce Campaign Members?

A campaign is an outbound marketing project that you want to plan, manage, and track within Salesforce. It can be a direct mail program, seminar, print advertisement, email, or other type of marketing initiative. You can organise campaigns into hierarchies for easy analysis of related marketing tactics. Salesforce Campaign members are the contacts and leads in your CRM that you included in the campaign and are trying to market to. If it's a direct mail campaign, it's the people you sent the mailing to. If it's a seminar, it's the people that you invited. If it's an email campaign, it's the people you sent the email to. You can then track their activity, such as if they clicked on a link in the email, if they rsvp'ed for the seminar, and if they actually showed up, etc. In Salesforce, when you visit a campaign record, the campaign members are a related list.