Based on where you are from, different countries have different terms for "storm drain".

Based on where you are from, different countries have different terms for "storm drain".
Accordingly to Wikipedia, a storm drain is largely a tunnel that carry runoffs (rain) from urban areas. For a layman, it helps to think along the line of sewage system that works beneath our cities.
In america, this is popularly known as "storm drain" or "storm sewer".
In the united kingdom, this is popularly known as "surface water drain" or "surface water sewer".
In Australia and New Zealand, it is also known as "stormwater drain".
And there it is, next time you hear someone mentioning "storm drain", "storm sewer", "surface water drain","surface water sewer" and "stormwater drain", congratulations, you know they refer to the exact same thing.
Functions of storm drain include draining excess water (rain or storm water) and ground water from pavement, streets and carparks into rivers and streams to protect yourself from flooding.
Although storm drains accomplish a amazing job of draining excess water from the urban areas, the inlets are essentially openings where left uncovered can pose a danger to pedestrians. Left uncovered, rubbish will enter the storm drains and cause choking which can eventually cause flooding.
In order to guarantee storm drains serve their purposes while minimizing street furniture posed to pedestrians and to prevent choking of the drains, drain covers (gratings) are used to cover the inlets (openings) of the storm drains to achieve the two purposes.
Over at Jonite, we concentrate on steel reinforced drain covers (gratings) for your storm drains while preserving the aesthetic components of the architecture around the drain covers.