The phrases "agree to" and "agree on" are close in meaning, but they’re used in slightly different contexts:
Agree to – This phrase is typically used when someone consents to a proposal, request, or arrangement. It often implies giving permission or approval to something.
Example: "She agreed to the terms of the contract."
Here, "agree to" means accepting or consenting to the contract's terms.
Agree on – This is used when two or more people reach a mutual decision or share the same opinion about something specific.
Example: "We all agreed on the best approach to the project."
In this case, "agree on" shows that everyone has come to the same conclusion about the project approach.
So, use "agree to" for accepting something that’s been proposed, and "agree on" when people come to a shared decision.