What is the area of grass in front of the house called?

In a residential area, a front yard (United States, Canada, Australia) or front garden (United Kingdom, Europe) is the portion of land between the street and the front of the house. If it is covered in grass, it may be referred to as a front lawn. The area behind the house, usually more private, is the backyard or back garden. Yard and garden share an etymology and have overlapping meanings.

Source: Wikipedia