What’s the difference between an i weathered rock and a highly weathered rock

weathered rock- Weathering breaks down and loosens the surface minerals of rock so they can be transported away by agents of erosion such as water, wind and ice. There are two types of weathering: mechanical and chemical. Mechanical Weathering. Mechanical weathering is the disintegration of rock into smaller and smaller fragments.  

Highly weathered rock- Moderately weathered Slight discoloration extends through greater part of rock mass. The rock is not friable. Discontinuities are stained and/or contain a filling comprising altered material. Highly (or severely) weathered Weathering extends throughout rock mass and the colored material is partly friable.