The account is the home for all related data. The account Is normally a company or some kind of organisation.

Contacts are individuals working at or connected to the company or organisation. 

Activities are all kinds of actions you take. An activity can be a scheduled meeting with a client,a follow up, a reminder or just a simple to do.

Opportunity is a potential deal. Opportunities helps you keep track of the progress of the deal, potential value, decision dates etc.

Leads are contacts and companies you've not yet qualified. A Lead is most of the time someone you've never been in contact with.

Projects can be used to follow consulting assignments, development projects, delivery projects, internal projects, contracts etc. Projects is used for complex processes where several people, businesses and activities are linked together.

Changes are all changes happening in Cirrus. For example; someone updating a customers phone number, creating a new account, updating an opportunity etc. 

Activity analysis summarizes all activities that's been created and done in Cirrus. Choose a specific period of time ans users to make the analysis as precise as you need it.

The pipeline analysis is based on your input in opportunities. Choose a specific period of time ans users to make the analysis as precise as you need it.

Sales analysis is based on your input in the add-on "order". Choose a specific period of time ans users to make the analysis as precise as you need it.