Selective herbicides, such as mecoprop are designed to target one type of plant, such as broadleaf plants, without affecting grasses.
Non-selective herbicides, such as Roundup® do not discriminate. They will kill any plants with which they come in contact.
Most minimum risk pesticides (those that are exempt from the registration process because they pose little or no risk to humans and the environment) are non-selective. For example, St. Gabriel Laboratories Burnout Weed and Grass Killer is “For non-selective control of herbaceous broadleaf and grass weeds” Application recommendations include: “Spot treatments in lawn, Mulch Beds, Flower Beds, Around Patios, Walkways, Fence Lines and Driveways. Safe for treating weeds between crops, but don’t spray the crops themselves.”