Someone or something that is productive produces or does a lot for the amount of resources used.
Training makes workers highly productive.
培训使工人们的工作效率很高。
More productive farmers have been able to provide cheaper food.
生产力更高的农民们已能提供更便宜的食品。
If you say that a relationship between people is productive, you mean that a lot of good or useful things happen as a result of it.
He was hopeful that the next round of talks would also be productive.
他对下一轮会谈也会富有成效充满了希望。