These are the 5 precepts. They are voluntary, but it is understood, that if one does not adhere to these precepts, one's actions will be unskillful, and they will lead one away from enlightenment. These 5 are the base of ethics.

Each one of these precepts has broad meaning, for instance to refrain from incorrect speech means no lies, no slander, no abusive speech, no idle chatter. It means to speak at the right time, when is beneficial, when the circumstances are right. It also means one should keep his mouth shut, unless one adds value to the convo, etc.

1.
I undertake the precept to refrain from destroying living creatures.
2.
I undertake the precept to refrain from taking that which is not given.
3.
I undertake the precept to refrain from sexual misconduct.
4.
I undertake the precept to refrain from incorrect speech.
5.
I undertake the precept to refrain from intoxicating drinks and drugs which lead to carelessness.