What is a project? What are the approaches to its definition?

A project is a unique venture with a beginning and end, conducted by people to meet established goals within parameters of cost, schedule and  quality.

Some of various elements of any projects are:

1. Projects are complex, one-time processes. 
2. Projects are limited by budget, schedule, and resources. 
3. Projects are developed to resolve a clear goal or set of goals.
4. Projects are customer-focused.