The Terms of Service is a commonly used phrase to describe the set of rules to agree to before using a service. You can see these Terms in Jaxx when you open the app for the first time and try to set or pair a wallet.
You can also revisit the Terms of Service inside Jaxx through the following steps:
Please go to the Menu (displayed as ☰ ) at the top right corner
Scroll down to About
Click on Terms of Service