The aquarium information site
by the experienced fish keeper / breeder.

All fishes found inland or in lakes are freshwater fish.
Freshwater is not salty like the sea or ocean.
If you bought your fish in a small corner fishshop, it is probably freshwater fish because saltwater fish is hard to keep in simple aquarium setups.

All fishes found in the big ocean or sea is saltwater.
If you see live corals in the tank, it is probably saltwater.
All fish found in the sea or ocean is saltwater fish. They are usually very colourful and brightly coloured. Some people call saltwater fish marine fish ( marine means sea or related to sea ).

I'm sure you know what is equipment and accessories you need to keep fish?
This section is everything that you see in the fish tank that is not found naturally in the fish habitat. This includes air-pumps, filters, heaters etc. We only talk about useful aquarium accessories here. Useless things will not be mentioned.

These are some great links you may want to use for research if you are interested in scientific documentation. These are information not in the "need to know" but is either interesting or may be helpful to fish researchers.