It is the present tense, third-person plural form of the verb "donner" (to give).
Here are some examples of how it can be used:
* On donne des fleurs aux invités. (We give flowers to the guests.)
* On donne beaucoup d'argent aux pauvres. (We give a lot of money to the poor.)
* On donne le meilleur de soi-même. (We give our best.)
Note: In French, "on" can be used as a general subject, referring to people in general or "one".