Hi Geneva- Glyphosate is the main active ingredient in Roundup branded herbicides.
Crops that have been genetically modified so that glyphosate doesn't harm them allows farmers to effectively control weeds by precisely targeting the invasive plants. This may mean farmers don't have to till or turn over their soil as much to control weeds, which can reduce GHG emissions and can reduce soil erosion.
Check out this video to learn more: What is glyphosate? - Give it a Minute