Is there that much of a difference between Inventor and Scientist?
Of course! Anyone could be an inventor if they are creative enough, not too many could be scientists however.
from the Wikipedia:
An inventor is a person who creates new inventions, typically technical devices such as mechanical, electrical or software devices or methods. Although some inventors may also be scientists, most of them are engineers in fact as they base their work on the discoveries of other scientists, experimenting with practical applications and combinations of those discoveries, and with improvements and combinations of existing devices, to create new useful devices.
A scientist is an expert in at least one area of science and who uses the scientific method to do research. At the request of the poet Coleridge in 1833, William Whewell coined the English word "scientist". Before this, it was "natural philosopher" or "man of science". Scientists have a passion to understand the world (and Universe), often from childhood. At one time science was not in the public eye, although technological advances have always altered human life and society. Now the activity of scientists, especially those involved in medicine, is widely known.
Is there a clear distinction between science and engineering? It's said that engineers are concerned with solving practical problems, while scientists ask "why" and engage in research. But scientists often perform engineering tasks such as designing experimental apparatus and building prototypes, while some engineers do first-rate research. If you say that engineers want to know how to solve a problem and implement the solution, you have also just described what most scientists do, though perhaps with different goals. The conventional wisdom is that scientists investigate phenomena, whereas engineers are concerned with solutions to practical problems. But mechanical, electrical, chemical and aerospace engineers are often at the forefront of investigating new phenomena. Peter Debye got a degree in electrical engineering before moving on to a doctorate in physics and a Nobel Prize in chemistry.
In general, it can be stated that a scientist builds in order to learn, but an engineer learns in order to build.