What is the difference between road anti-icing and deicing?

Anti-icing is a proactive approach taken to decrease the likelihood of snow and ice bonding to a pavement surface. Additionally, anti-icing can prevent frost from forming on pavement surfaces. Anti-icing involves placing a layer of brine on the surface of the pavement before a winter storm has begun. This layer prevents the snow and ice from freezing to (or icing onto) the road. The alternative— which is called deicing—is to let the snow bond/freeze to the road, then apply pre-wetted rock salt to break the bond between the snow and the pavement. Studies have shown that anti-icing will achieve the same level of service on a road or highway using between one-quarter and one-fifth the amount of salt used in deicing. Typically, anti-icing is performed using trucks carrying tanks, which have pumps to spray the brine onto the pavement surfaces. In many places lines or stripes of brine can be seen on a road before a given event. Some people call these safety stripes! Usually, brine is applied at rates of between 30 and 50 gallons per lane mile.

Source: https://professionalsnowfightersassociation.org/wp-content/uploads/2019/04/16PUB_BrineFactSheet_Spring2016_FINAL1-copy.pdf