After picking a time period of your choice, the Renewal Rate will give you a quick overview of your basic SaaS metrics. It'll look something like this:
Click the image to view it enlarged
You can click each box to learn more about the accounts that fell into each KPI.
Base - means the Renewal Base, which are all of the Licenses coming up for renewal during that period.
Renewal - means the accounts/subscriptions that actually were renewed during that period.
Upgrade - means the accounts/subscriptions that were up-sold, cross-sold, or were upgraded during that period.
New Biz - means the accounts/subscriptions that were net new during that period (new sales).
Downgrades - means the accounts/subscriptions that were downgraded - subscriptions that had an MRR decrease during the time period.
Churn - means the accounts/subscriptions that was lost.