An entrepreneur is a person who organizes and manages a business undertaking, assuming the risk for the sake of profit.
An entrepreneur: Sees an opportunity. Makes a plan. Starts the business. Manages the business. Receives the profits.
Entrepreneurship is the concept of running a business never has been in the market, a new kind of product/ service/ idea/ etc. Being new in the market makes it riskier hence the business ower is called entrepreneur.