What you need to know:
Bitumen by definition is a variety of mixtures of hydrocarbons, derived from the refining of crude oil. It is a thermoplastic material, meaning that it becomes pliable or moldable above a specific temperature and returns to a solid-state upon cooling.
Penetration-grade bitumen is mainly used in road surfacing. Bitumen with lower penetration grade is used in the regions with warm climate while higher penetration grade is used in colder weather.