Permeable block paving is designed to allow rainwater and precipitation to soak-away beneath the driveway or paved areas to help prevent run-off when adjacent soak-away areas (lawns, beds etc) are not available.
Permeable block paving allows rainfall to drain between the bricks to naturally soak-away fulfilling source control criteria as part of Sustainable Urban Drainage (SUDS).
Premeable blocks help prevent localised surface flooding when mains drainage becomes overwhelmed; it does this by keeping rainfall on your property where it will soak-away, rather than letting it run into the roads and drains.
If you are using permeable paving to pave your own domestic driveway or area at the front of your property, then you can do so without applying for planning permission.
Permeable paving should be considered by housebuilders and developers for both your Sustainable Urban Drainage (SUDS) plan and to ensure you're aligned with BREEAM advice to assist you with any planning application you're undertaking.