When you click into a single prospect, you'll see several tabs on the top of the page - "Overview", "Activity", "Emails", and "Sequences". Each of these tabs provide important information related to your prospect and understanding the difference between them is important to understand for your outreach.
When you click into a prospect from the prospect list view, Outreach defaults to the overview tab. The overview tab displays Sales Intelligence Tiles for curated information on your prospect, their company, and recent activity on the prospect or account. These are based on your preferences and can be modified to fit your needs.
The prospect activity tab shows all activity on the prospect. This includes emails, but also shows any updates made to the prospect by Outreach, Salesforce, or an Outreach user. It is a comprehensive list of updates and activity which can then be filtered to show the information you're most interested in.
The emails tab shows inbound and outbound emails sent to the prospect and removes all other system activity. It's a summary of communication between the prospect and the Outreach user.
The sequences tab displays all past and current sequences the prospect has been added to. If the sequence is active, the toggle next to the sequence name is green. If inactive, the sequence is grey.