A freelancer works on a project to project basis, to do the actual work requested, and bills on a project, or hourly basis, depending on the amount of work expected. The freelancer usually works at their own home or office, but - where possible, will often meet with the client ( you ) a few times: At the very beginning of a project, and part way through, if there are special things that need to be done, in my case, such as scanning valuable documents you don't want leaving your possession, or coming to your home or business to find out why a wireless router works intermittently.
In most cases a Freelancer will have a fixed or hourly price for completing projects, let's say, $25 for designing and procuring print services for a business card, $150 for a brochure, $500-1000 for a website setup and hourly rates for ongoing maintenance. However, at the end of the project, or multiple projects, the project is considered complete, and final payment is tendered. Usually there will be an up-front deposit, and more payment based on milestones, if it a larger project. Even during a project, the Freelancer is free to start other projects with other clients. However, by contract, they are bound to complete the work the client requests.
A Consultant works on your premises - usually a business, and works for a longer term, usually multiple projects, and may retain outside help ( subcontract ) for portions of the work that needs to be done.
In some cases the Consultant may act as an adviser, and manage internal projects, rather than do the actual work; the value is that their expertise will help complete the project where a direct manager may not have the time or expertise to successfully guide their staff through to completion, or process.
While it may sound similar, the key differences are longevity and scope of project(s), and also the possibility of hiring the Contractor as part of your team, to become a part or full time employee. Payment is usually tendered weekly, biweekly, or monthly, and is based on a set hourly rate, regardless of projects completed, as it is ongoing oversight, or advise to the client. For instance, it might be a case where a sales manager needs a trainer to come in and help train crews who are then sent out to various locations, to be replaced by a new set of crew to be sent to more locations. Another example would be to perform " Marketing Services " which would include Branding, Logo development, Print collateral, two or three websites, and launch various social media campaigns.
Of course, you wouldn't lend out money on a handshake and a verbal - "Pay me back each month plus 6% and we'll all be happy".
For Freelancers, the contract is all important. It clearly states the scope of work to be done, and deadlines, and sets expectations for the Freelancer AND the Client. If either party does not live up to the contract, it is considered broken. and each is free to 'walk away'.
The contract can also help determine if work is done on a per hour or per project basis.
It helps define what the responsibilities of each are, for instance if the client is required to produce all graphics and copy for the Freelancer to then arrange, or if the Freelancer is expected to produce artwork, and act as copywriter
(which of course, would be more costly).
So - NEVER HIRE A FREELANCER WITHOUT A CONTRACT.
For consulting, there may not be a contract, but ongoing expectations, where the client stipulates the expectations, and the Contractor is obligated to those stipulations.
As such, if I am already contracting for a client, I will let you know and advise you to find another person for the project you wish, as my sole purpose in life will be to fulfill the life-cycle of the clients ongoing requests. Sort of like 'real work'