what is the difference between orange juice and from concentrate?!

The 'From concentrate' type has some water removed before it's bulk shipped, to lower the transport costs.

Water is then added back at the packaging plant, to give it the same strength as the original juice.

I can't tell the difference between the two types, some people say they can.

Robert J gave a good answer. I am one of those that can tell the difference and prefer juice that is not from concentrate. There are several on the market that are good, but "Simply Orange" bottles a great tasting juice. Almost as good as squeezing the oranges yourself.

Pure orange juice is pure, and orange juice from concentrate is healthy, but not as healthy as it is waterd down,