What is the difference between "short-term concentrated heavy precipitation" and "rainstorm"

Definition of short-term heavy rainfall:

Short-term heavy precipitation refers to the weather phenomenon that the precipitation intensity is relatively high in a short period of time and the rainfall reaches or exceeds a certain value. The regulation of this value varies from place to place, and the hourly rainfall is generally ≥ 20 mm.

Characteristics of short-term heavy rainfall:

Short-term heavy rainfall has the characteristics of sudden, violent, concentrated precipitation time and short predictable time. Due to the high intensity and concentrated time of precipitation, short-term heavy precipitation often leads to meteorological disasters such as urban waterlogging and landslides, which seriously affects urban operation and even threatens life.

Definition of rainstorm:

Heavy rain is rain with strong precipitation intensity. It is raining cats and dogs, which generally refers to the precipitation with an hourly rainfall exceeding 16 mm, or a continuous 12 hour rainfall exceeding 30 mm, or a continuous rainfall exceeding 50 mm for 24 hours. According to China's meteorological regulations, heavy rainfall with a precipitation of more than 50 mm in 24 hours is called "rainstorm". Due to the different characteristics of precipitation and topography, the standards of rainstorm and flood are different in different places.

Characteristics of rainstorm:

To produce rainstorm, there must be enough water vapor, strong and lasting upward movement of airflow and instability of atmospheric structure. The favorable combination of weather system and underlying surface, especially topography, can produce heavy rain. Rainstorms often fall from cumulonimbus clouds. The updraft in the cumulonimbus cloud is very strong, the vertical speed can reach 20 ~ 30m/s, and the maximum speed can reach 60m/s, even higher than the wind speed of typhoon. In the strong updraft, the water droplets keep increasing, and the water droplets in the cloud drop sharply to the ground until the updraft can't support it.