An Independent Contractor Agreement is used when you are hiring a contractor. The difference between an employee and an independent contractor is, that with an independent contractor you only have say about the final job that is to be done, and not about methods, timings, materials used etc. It can be signed when you will be completing projects for  a person/company from time to time, or when you will be receiving services from an independent contractor. In it, you can specify the terms of the job, the payment structure, and estimate the amount of time the job will take and more details.