The name Barramundi, is Aboriginal and originates from the North Queensland region, that translates something like, 'large scaley fish'.
In the larger scale of things, the barramundi is a species of sea bass. With close relatives in Asia Pacific: throughout PNG, Indonesia, Thailand, and many more countries nearby Australia. The fish is described as a euryhaline fish: meaning that it can adapt to live in a wide variety of saltwater conditions. As a result, you can find large adult fish living in estuaries around northern Australia. However, fish destined to live permanently in salt water must grow up in brackish water in order to develop properly first. Making the fishes lifestyle more like the bass; however, they are destined to live in fresh water.
However, with all of that said. The fish is actually far better known for its relationship with food. This fish has been popular with local Aborigines and is featured in rock art in this region dating back at least 15000 years. Rock art can be seen in the hyperlink provided. In Asia, sea bass is very popular in Thai dishes, Bengali cuisine, and Australia farms and exports hundreds of fish each year around the world. This fish is popular simply because it tastes good.