Fair trade is an idea that comes from the fact that some people in some countries do not get very much for all the effort they put in to growing crops or making goods. That is, they get an unfairly small part of the money customers eventually pay.
The amount that poor farmers in some developing countries get paid, for example, is very low compared to the amount people pay in our country. So the idea of fair trade was to help these people club together and so have more of a bargaining position with the people who bought their goods.
But this did not work at first. People in the buying countries had to be made aware of the problem so they wanted to buy fair trade goods.
The idea of fair trade can now be found in coffee, bananas, textiles and crafts.
The whole problem of helping poor people to get better wages has not been solved, but this is a step on the way.
The link below takes you to over 20 videos that look at fair trade and people at work in the developing world. Start with video 1, about Ugandan bananas.