There are a number of ways in which the US economy is different from that of various other nations. The specific differences vary from nation to nation. Let us look at two of these differences.
For example, the US economy is different from the economy of a developing nation in that it is much more oriented towards the tertiary sector of the economy. The US does not have a very high percentage of its workforce working in the primary and secondary sectors. This is in contrast to countries like Kenya or Bangladesh which would have many more workers in those sectors.
The US economy also differs to some degree from those of other rich nations. For example, the US economy is much less regulated than those of many European countries or even Japan. The US has very few laws that affect the terms of contracts that businesses can enter into with their workers. Other countries tend to do things like regulating the situations in which firms may lay off employees. The US does not do this and, as a consequence, its economy is somewhat more flexible than those of many other rich nations.
Thus, the US economy differs both from the economies of poorer nations and, to some degree, from the economies of other rich nations.