Total weed killers are also often referred to as 'non selective' weed killers. This is because they do not differentiate between something you want to control and something you want to keep.  Total weed killers are ideal for controlling weeds in amenity situations, for controlling weeds on pathways,  gravel driveways, patios, or for areas of non cropped land. 

Total weed killers are 'contact sprays' as they only control the weeds they come into contact with, but do not prevent new weeds from germinating.