In a farmers’ market, most food has been harvested between 10 and 24 hours before you buy it, and they will be fresh and juicy. Unlike supermarkets' which has been harvested weeks or even months ago.If you buy local food you are supporting your countrys' or towns' farmers and people.
Also, in farms that work for supermarkets lots of pesticides and preservatives are used, and all of those chemicals go right into your body. Most of the food you find in a supermarket probably came from places you have never even heard of. 
Maybe if they say made in (your country) or product made in (your country) it was made in your country, and it is better to buy it because your supporting YOUR people, but it probably has pesticides and all those chemicals you don't want in your body to. 
If you want to know HOW, WHEN or WHERE your food was harvested go to a farmers' market! There you will have the chance to dialog with the farmer and ask him (or her) where, how and when did he make the food or all those questions you have about what YOU are eating. 