According to the Product Development and Management Association (PDMA), a "Concept: A clearly written and possibly visual description of the new product idea that includes its primary features and consumer benefits, combined with a broad understanding of the technology needed."
Here is a great example from Ipsos.
The U.S. Small Business Administration (SBA) defines a "small business" as one with fewer than 500 employess and less than $7 million in sales. That seems pretty big to me! There is a federal office in Fresno, and information specific to the region.
And, don't forget your permits!